diff --git a/dd-java-agent/instrumentation/play/play-appsec-2.5/src/main/java/datadog/trace/instrumentation/play25/appsec/BodyParserHelpers.java b/dd-java-agent/instrumentation/play/play-appsec-2.5/src/main/java/datadog/trace/instrumentation/play25/appsec/BodyParserHelpers.java
index 16f0309e4bc..0eba7744dff 100644
--- a/dd-java-agent/instrumentation/play/play-appsec-2.5/src/main/java/datadog/trace/instrumentation/play25/appsec/BodyParserHelpers.java
+++ b/dd-java-agent/instrumentation/play/play-appsec-2.5/src/main/java/datadog/trace/instrumentation/play25/appsec/BodyParserHelpers.java
@@ -12,13 +12,19 @@
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.fasterxml.jackson.databind.node.TextNode;
 import datadog.appsec.api.blocking.BlockingException;
+import datadog.trace.api.Config;
 import datadog.trace.api.gateway.BlockResponseFunction;
 import datadog.trace.api.gateway.CallbackProvider;
 import datadog.trace.api.gateway.Flow;
 import datadog.trace.api.gateway.RequestContext;
 import datadog.trace.api.gateway.RequestContextSlot;
+import datadog.trace.api.http.MultipartContentDecoder;
+import datadog.trace.api.internal.VisibleForTesting;
 import datadog.trace.bootstrap.instrumentation.api.AgentSpan;
 import datadog.trace.bootstrap.instrumentation.api.AgentTracer;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.InputStream;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -54,6 +60,15 @@ public class BodyParserHelpers {
   // cause muzzle to disable the instrumentation for Play 2.7.
   private static final Method MULTIPART_FILES_METHOD;
 
+  // Cached via reflection: FilePart.ref() returns the generic file reference (TemporaryFile in
+  // Play 2.5/2.6), and TemporaryFile.file() returns java.io.File. Using reflection avoids
+  // embedding bytecode references to TemporaryFile that could break muzzle.
+  private static final Method FILE_PART_REF;
+  private static final Method TEMP_FILE_FILE;
+
+  public static final int MAX_CONTENT_BYTES = Config.get().getAppSecMaxFileContentBytes();
+  public static final int MAX_FILES_TO_INSPECT = Config.get().getAppSecMaxFileContentCount();
+
   static {
     Method m = null;
     try {
@@ -61,6 +76,24 @@ public class BodyParserHelpers {
     } catch (Exception ignored) {
     }
     MULTIPART_FILES_METHOD = m;
+
+    Method ref = null;
+    Method file = null;
+    try {
+      ref = MultipartFormData.FilePart.class.getMethod("ref");
+    } catch (Exception ignored) {
+    }
+    try {
+      file =
+          Class.forName(
+                  "play.api.libs.Files$TemporaryFile",
+                  false,
+                  BodyParserHelpers.class.getClassLoader())
+              .getMethod("file");
+    } catch (Exception ignored) {
+    }
+    FILE_PART_REF = ref;
+    TEMP_FILE_FILE = file;
   }
 
   private static JFunction1<
@@ -148,6 +181,22 @@ private static MultipartFormData<?> handleMultipartFormData(MultipartFormData<?>
       log.debug("Error handling multipartFormData filenames", e);
     }
 
+    if (pendingBlock == null) {
+      try {
+        if (MULTIPART_FILES_METHOD != null) {
+          Object files = MULTIPART_FILES_METHOD.invoke(data);
+          if (files instanceof scala.collection.Iterable) {
+            handleMultipartFilesContent(
+                new ScalaIteratorAdapter(((scala.collection.Iterable<?>) files).iterator()));
+          }
+        }
+      } catch (BlockingException be) {
+        pendingBlock = be;
+      } catch (Exception e) {
+        log.debug("Error handling multipartFormData files content", e);
+      }
+    }
+
     if (pendingBlock != null) throw pendingBlock;
     return data;
   }
@@ -176,6 +225,7 @@ private static void handleMultipartFilenames(java.util.Iterator<?> iterator) {
     executeFilenamesCallback(reqCtx, callback, filenames);
   }
 
+  @VisibleForTesting
   static List<String> collectFilenames(java.util.Iterator<?> iterator) {
     List<String> filenames = new ArrayList<>();
     while (iterator.hasNext()) {
@@ -206,6 +256,91 @@ private static void executeFilenamesCallback(
     }
   }
 
+  private static void handleMultipartFilesContent(java.util.Iterator<?> iterator) {
+    AgentSpan span = activeSpan();
+    if (span == null) {
+      return;
+    }
+    RequestContext reqCtx = span.getRequestContext();
+    if (reqCtx == null || reqCtx.getData(RequestContextSlot.APPSEC) == null) {
+      return;
+    }
+
+    CallbackProvider cbp = AgentTracer.get().getCallbackProvider(RequestContextSlot.APPSEC);
+    BiFunction<RequestContext, List<String>, Flow<Void>> callback =
+        cbp.getCallback(EVENTS.requestFilesContent());
+    if (callback == null) {
+      return;
+    }
+
+    List<String> contents = collectFilesContent(iterator);
+    if (contents.isEmpty()) {
+      return;
+    }
+
+    executeFilesContentCallback(reqCtx, callback, contents);
+  }
+
+  @VisibleForTesting
+  static List<String> collectFilesContent(java.util.Iterator<?> iterator) {
+    List<String> contents = new ArrayList<>(MAX_FILES_TO_INSPECT);
+    while (iterator.hasNext() && contents.size() < MAX_FILES_TO_INSPECT) {
+      MultipartFormData.FilePart<?> part = (MultipartFormData.FilePart<?>) iterator.next();
+      // null filename → no Content-Disposition filename attribute → form field → skip
+      // empty filename → file upload with no name → content still inspected
+      if (part.filename() == null) {
+        continue;
+      }
+      contents.add(readFilePartContent(part));
+    }
+    return contents;
+  }
+
+  @VisibleForTesting
+  static String readFilePartContent(MultipartFormData.FilePart<?> part) {
+    if (FILE_PART_REF == null || TEMP_FILE_FILE == null) {
+      return "";
+    }
+    try {
+      Object ref = FILE_PART_REF.invoke(part);
+      if (ref == null) {
+        return "";
+      }
+      Object fileObj = TEMP_FILE_FILE.invoke(ref);
+      if (!(fileObj instanceof File)) {
+        return "";
+      }
+      String contentType = null;
+      scala.Option<?> ct = (scala.Option<?>) part.contentType();
+      if (ct != null && ct.isDefined()) {
+        contentType = (String) ct.get();
+      }
+      try (InputStream is = new FileInputStream((File) fileObj)) {
+        return MultipartContentDecoder.readInputStream(is, MAX_CONTENT_BYTES, contentType);
+      }
+    } catch (Exception ignored) {
+      return "";
+    }
+  }
+
+  private static void executeFilesContentCallback(
+      RequestContext reqCtx,
+      BiFunction<RequestContext, List<String>, Flow<Void>> callback,
+      List<String> contents) {
+    Flow<Void> flow = callback.apply(reqCtx, contents);
+    Flow.Action action = flow.getAction();
+    if (action instanceof Flow.Action.RequestBlockingAction) {
+      Flow.Action.RequestBlockingAction rba = (Flow.Action.RequestBlockingAction) action;
+      BlockResponseFunction brf = reqCtx.getBlockResponseFunction();
+      if (brf != null) {
+        boolean success = brf.tryCommitBlockingResponse(reqCtx.getTraceSegment(), rba);
+        if (success) {
+          throw new BlockingException("Blocked request (multipart file upload content)");
+        }
+      }
+    }
+  }
+
   public static Function1<JsValue, JsValue> getHandleJsonF() {
     return HANDLE_JSON;
   }
diff --git a/dd-java-agent/instrumentation/play/play-appsec-2.5/src/test/groovy/datadog/trace/instrumentation/play25/server/PlayServerTest.groovy b/dd-java-agent/instrumentation/play/play-appsec-2.5/src/test/groovy/datadog/trace/instrumentation/play25/server/PlayServerTest.groovy
index 76e4dfbc7f2..fd10be014f3 100644
--- a/dd-java-agent/instrumentation/play/play-appsec-2.5/src/test/groovy/datadog/trace/instrumentation/play25/server/PlayServerTest.groovy
+++ b/dd-java-agent/instrumentation/play/play-appsec-2.5/src/test/groovy/datadog/trace/instrumentation/play25/server/PlayServerTest.groovy
@@ -88,6 +88,11 @@ class PlayServerTest extends HttpServerTest<Server> {
     true
   }
 
+  @Override
+  boolean testBodyFilesContent() {
+    true
+  }
+
   @Override
   boolean testBlocking() {
     true
diff --git a/dd-java-agent/instrumentation/play/play-appsec-2.6/src/main/java/datadog/trace/instrumentation/play26/appsec/BodyParserHelpers.java b/dd-java-agent/instrumentation/play/play-appsec-2.6/src/main/java/datadog/trace/instrumentation/play26/appsec/BodyParserHelpers.java
index c5004dc3bbb..4f1fff4b5fa 100644
--- a/dd-java-agent/instrumentation/play/play-appsec-2.6/src/main/java/datadog/trace/instrumentation/play26/appsec/BodyParserHelpers.java
+++ b/dd-java-agent/instrumentation/play/play-appsec-2.6/src/main/java/datadog/trace/instrumentation/play26/appsec/BodyParserHelpers.java
@@ -12,13 +12,19 @@
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.fasterxml.jackson.databind.node.TextNode;
 import datadog.appsec.api.blocking.BlockingException;
+import datadog.trace.api.Config;
 import datadog.trace.api.gateway.BlockResponseFunction;
 import datadog.trace.api.gateway.CallbackProvider;
 import datadog.trace.api.gateway.Flow;
 import datadog.trace.api.gateway.RequestContext;
 import datadog.trace.api.gateway.RequestContextSlot;
+import datadog.trace.api.http.MultipartContentDecoder;
+import datadog.trace.api.internal.VisibleForTesting;
 import datadog.trace.bootstrap.instrumentation.api.AgentSpan;
 import datadog.trace.bootstrap.instrumentation.api.AgentTracer;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.InputStream;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -64,6 +70,15 @@ public class BodyParserHelpers {
   // cause muzzle to disable the instrumentation for Play 2.7.
   private static final Method MULTIPART_FILES_METHOD;
 
+  // Cached via reflection: FilePart.ref() returns the generic file reference (TemporaryFile in
+  // Play 2.5/2.6), and TemporaryFile.file() returns java.io.File. Using reflection avoids
+  // embedding bytecode references to TemporaryFile that could break muzzle.
+  private static final Method FILE_PART_REF;
+  private static final Method TEMP_FILE_FILE;
+
+  public static final int MAX_CONTENT_BYTES = Config.get().getAppSecMaxFileContentBytes();
+  public static final int MAX_FILES_TO_INSPECT = Config.get().getAppSecMaxFileContentCount();
+
   static {
     Method m = null;
     try {
@@ -71,6 +86,24 @@ public class BodyParserHelpers {
     } catch (Exception ignored) {
     }
     MULTIPART_FILES_METHOD = m;
+
+    Method ref = null;
+    Method file = null;
+    try {
+      ref = MultipartFormData.FilePart.class.getMethod("ref");
+    } catch (Exception ignored) {
+    }
+    try {
+      file =
+          Class.forName(
+                  "play.api.libs.Files$TemporaryFile",
+                  false,
+                  BodyParserHelpers.class.getClassLoader())
+              .getMethod("file");
+    } catch (Exception ignored) {
+    }
+    FILE_PART_REF = ref;
+    TEMP_FILE_FILE = file;
   }
 
   private static JFunction1<
@@ -159,6 +192,22 @@ private static MultipartFormData<?> handleMultipartFormData(MultipartFormData<?>
       log.debug("Error handling multipartFormData filenames", e);
     }
 
+    if (pendingBlock == null) {
+      try {
+        if (MULTIPART_FILES_METHOD != null) {
+          Object files = MULTIPART_FILES_METHOD.invoke(data);
+          if (files instanceof scala.collection.Iterable) {
+            handleMultipartFilesContent(
+                new ScalaIteratorAdapter(((scala.collection.Iterable<?>) files).iterator()));
+          }
+        }
+      } catch (BlockingException be) {
+        pendingBlock = be;
+      } catch (Exception e) {
+        log.debug("Error handling multipartFormData files content", e);
+      }
+    }
+
     if (pendingBlock != null) throw pendingBlock;
     return data;
   }
@@ -187,6 +236,7 @@ private static void handleMultipartFilenames(java.util.Iterator<?> iterator) {
     executeFilenamesCallback(reqCtx, callback, filenames);
   }
 
+  @VisibleForTesting
   static List<String> collectFilenames(java.util.Iterator<?> iterator) {
     List<String> filenames = new ArrayList<>();
     while (iterator.hasNext()) {
@@ -217,6 +267,91 @@ private static void executeFilenamesCallback(
     }
   }
 
+  private static void handleMultipartFilesContent(java.util.Iterator<?> iterator) {
+    AgentSpan span = activeSpan();
+    if (span == null) {
+      return;
+    }
+    RequestContext reqCtx = span.getRequestContext();
+    if (reqCtx == null || reqCtx.getData(RequestContextSlot.APPSEC) == null) {
+      return;
+    }
+
+    CallbackProvider cbp = AgentTracer.get().getCallbackProvider(RequestContextSlot.APPSEC);
+    BiFunction<RequestContext, List<String>, Flow<Void>> callback =
+        cbp.getCallback(EVENTS.requestFilesContent());
+    if (callback == null) {
+      return;
+    }
+
+    List<String> contents = collectFilesContent(iterator);
+    if (contents.isEmpty()) {
+      return;
+    }
+
+    executeFilesContentCallback(reqCtx, callback, contents);
+  }
+
+  @VisibleForTesting
+  static List<String> collectFilesContent(java.util.Iterator<?> iterator) {
+    List<String> contents = new ArrayList<>(MAX_FILES_TO_INSPECT);
+    while (iterator.hasNext() && contents.size() < MAX_FILES_TO_INSPECT) {
+      MultipartFormData.FilePart<?> part = (MultipartFormData.FilePart<?>) iterator.next();
+      // null filename → no Content-Disposition filename attribute → form field → skip
+      // empty filename → file upload with no name → content still inspected
+      if (part.filename() == null) {
+        continue;
+      }
+      contents.add(readFilePartContent(part));
+    }
+    return contents;
+  }
+
+  @VisibleForTesting
+  static String readFilePartContent(MultipartFormData.FilePart<?> part) {
+    if (FILE_PART_REF == null || TEMP_FILE_FILE == null) {
+      return "";
+    }
+    try {
+      Object ref = FILE_PART_REF.invoke(part);
+      if (ref == null) {
+        return "";
+      }
+      Object fileObj = TEMP_FILE_FILE.invoke(ref);
+      if (!(fileObj instanceof File)) {
+        return "";
+      }
+      String contentType = null;
+      scala.Option<?> ct = (scala.Option<?>) part.contentType();
+      if (ct != null && ct.isDefined()) {
+        contentType = (String) ct.get();
+      }
+      try (InputStream is = new FileInputStream((File) fileObj)) {
+        return MultipartContentDecoder.readInputStream(is, MAX_CONTENT_BYTES, contentType);
+      }
+    } catch (Exception ignored) {
+      return "";
+    }
+  }
+
+  private static void executeFilesContentCallback(
+      RequestContext reqCtx,
+      BiFunction<RequestContext, List<String>, Flow<Void>> callback,
+      List<String> contents) {
+    Flow<Void> flow = callback.apply(reqCtx, contents);
+    Flow.Action action = flow.getAction();
+    if (action instanceof Flow.Action.RequestBlockingAction) {
+      Flow.Action.RequestBlockingAction rba = (Flow.Action.RequestBlockingAction) action;
+      BlockResponseFunction brf = reqCtx.getBlockResponseFunction();
+      if (brf != null) {
+        boolean success = brf.tryCommitBlockingResponse(reqCtx.getTraceSegment(), rba);
+        if (success) {
+          throw new BlockingException("Blocked request (multipart file upload content)");
+        }
+      }
+    }
+  }
+
   public static Function1<JsValue, JsValue> getHandleJsonF() {
     return HANDLE_JSON;
   }
diff --git a/dd-java-agent/instrumentation/play/play-appsec-2.6/src/test/groovy/datadog/trace/instrumentation/play26/server/PlayAsyncServerTest.groovy b/dd-java-agent/instrumentation/play/play-appsec-2.6/src/test/groovy/datadog/trace/instrumentation/play26/server/PlayAsyncServerTest.groovy
index 339c17ff797..fdf35a116f9 100644
--- a/dd-java-agent/instrumentation/play/play-appsec-2.6/src/test/groovy/datadog/trace/instrumentation/play26/server/PlayAsyncServerTest.groovy
+++ b/dd-java-agent/instrumentation/play/play-appsec-2.6/src/test/groovy/datadog/trace/instrumentation/play26/server/PlayAsyncServerTest.groovy
@@ -13,6 +13,11 @@ class PlayAsyncServerTest extends AbstractPlayServerTest {
     true
   }
 
+  @Override
+  boolean testBodyFilesContent() {
+    true
+  }
+
   @Shared
   def executor
 
diff --git a/dd-java-agent/instrumentation/play/play-appsec-2.6/src/test/groovy/datadog/trace/instrumentation/play26/server/PlayServerTest.groovy b/dd-java-agent/instrumentation/play/play-appsec-2.6/src/test/groovy/datadog/trace/instrumentation/play26/server/PlayServerTest.groovy
index b48ff0ad201..0ac729a38ac 100644
--- a/dd-java-agent/instrumentation/play/play-appsec-2.6/src/test/groovy/datadog/trace/instrumentation/play26/server/PlayServerTest.groovy
+++ b/dd-java-agent/instrumentation/play/play-appsec-2.6/src/test/groovy/datadog/trace/instrumentation/play26/server/PlayServerTest.groovy
@@ -12,6 +12,11 @@ class PlayServerTest extends AbstractPlayServerTest {
     true
   }
 
+  @Override
+  boolean testBodyFilesContent() {
+    true
+  }
+
   def 'test instrumentation gateway xml request body'() {
     setup:
     def request = request(
diff --git a/dd-java-agent/instrumentation/undertow/undertow-2.0/src/main/java/datadog/trace/instrumentation/undertow/FormDataContentHelper.java b/dd-java-agent/instrumentation/undertow/undertow-2.0/src/main/java/datadog/trace/instrumentation/undertow/FormDataContentHelper.java
new file mode 100644
index 00000000000..9901a9b67b9
--- /dev/null
+++ b/dd-java-agent/instrumentation/undertow/undertow-2.0/src/main/java/datadog/trace/instrumentation/undertow/FormDataContentHelper.java
@@ -0,0 +1,99 @@
+package datadog.trace.instrumentation.undertow;
+
+import datadog.trace.api.Config;
+import datadog.trace.api.http.MultipartContentDecoder;
+import datadog.trace.api.internal.VisibleForTesting;
+import io.undertow.server.handlers.form.FormData;
+import io.undertow.util.HeaderMap;
+import io.undertow.util.Headers;
+import java.io.InputStream;
+import java.lang.reflect.Method;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public final class FormDataContentHelper {
+
+  private static final Logger log = LoggerFactory.getLogger(FormDataContentHelper.class);
+
+  public static final int MAX_CONTENT_BYTES = Config.get().getAppSecMaxFileContentBytes();
+  public static final int MAX_FILES_TO_INSPECT = Config.get().getAppSecMaxFileContentCount();
+
+  // Undertow 2.2+ added getFileItem() to FormValue for in-memory uploads.
+  // In 2.0 all uploads are always on disk so getPath() suffices.
+  private static final Method GET_FILE_ITEM;
+  private static final Method FILE_ITEM_GET_INPUT_STREAM;
+
+  static {
+    Method gfi = null;
+    Method gis = null;
+    try {
+      gfi = FormData.FormValue.class.getMethod("getFileItem");
+      gis = gfi.getReturnType().getMethod("getInputStream");
+    } catch (Exception ignored) {
+    }
+    GET_FILE_ITEM = gfi;
+    FILE_ITEM_GET_INPUT_STREAM = gis;
+  }
+
+  public static List<String> collectContents(FormData attachment) {
+    List<String> result = new ArrayList<>(MAX_FILES_TO_INSPECT);
+    for (String key : attachment) {
+      for (FormData.FormValue formValue : attachment.get(key)) {
+        if (result.size() >= MAX_FILES_TO_INSPECT) {
+          return result;
+        }
+        try {
+          // null means no filename attribute → form field → skip
+          if (formValue.getFileName() == null) {
+            continue;
+          }
+          result.add(readContent(formValue));
+        } catch (Exception e) {
+          log.debug("Failed to process form value", e);
+        }
+      }
+    }
+    return result;
+  }
+
+  @VisibleForTesting
+  static String readContent(FormData.FormValue formValue) {
+    String contentType = null;
+    HeaderMap headers = formValue.getHeaders();
+    if (headers != null) {
+      contentType = headers.getFirst(Headers.CONTENT_TYPE);
+    }
+
+    // Try getPath() first: works for 2.0 (all files on disk) and 2.2+ disk files.
+    try {
+      Path path = formValue.getPath();
+      try (InputStream is = Files.newInputStream(path)) {
+        return MultipartContentDecoder.readInputStream(is, MAX_CONTENT_BYTES, contentType);
+      }
+    } catch (Exception ignored) {
+      // In Undertow 2.2+, in-memory uploads throw here (no path).
+    }
+
+    // Fallback for Undertow 2.2+ in-memory uploads via cached reflection.
+    if (GET_FILE_ITEM != null && FILE_ITEM_GET_INPUT_STREAM != null) {
+      try {
+        Object fileItem = GET_FILE_ITEM.invoke(formValue);
+        if (fileItem != null) {
+          try (InputStream is = (InputStream) FILE_ITEM_GET_INPUT_STREAM.invoke(fileItem)) {
+            return MultipartContentDecoder.readInputStream(is, MAX_CONTENT_BYTES, contentType);
+          }
+        }
+      } catch (Exception e) {
+        log.debug("Failed to read in-memory upload via reflection", e);
+      }
+    }
+
+    return "";
+  }
+
+  private FormDataContentHelper() {}
+}
diff --git a/dd-java-agent/instrumentation/undertow/undertow-2.0/src/main/java/datadog/trace/instrumentation/undertow/MultiPartUploadHandlerInstrumentation.java b/dd-java-agent/instrumentation/undertow/undertow-2.0/src/main/java/datadog/trace/instrumentation/undertow/MultiPartUploadHandlerInstrumentation.java
index 52bd0b73897..d811682eeca 100644
--- a/dd-java-agent/instrumentation/undertow/undertow-2.0/src/main/java/datadog/trace/instrumentation/undertow/MultiPartUploadHandlerInstrumentation.java
+++ b/dd-java-agent/instrumentation/undertow/undertow-2.0/src/main/java/datadog/trace/instrumentation/undertow/MultiPartUploadHandlerInstrumentation.java
@@ -53,7 +53,7 @@ public Reference[] additionalMuzzleReferences() {
 
   @Override
   public String[] helperClassNames() {
-    return new String[] {packageName + ".FormDataMap"};
+    return new String[] {packageName + ".FormDataMap", packageName + ".FormDataContentHelper"};
   }
 
   public void methodAdvice(MethodTransformer transformer) {
@@ -87,7 +87,9 @@ static void after(
           cbp.getCallback(EVENTS.requestBodyProcessed());
       BiFunction<RequestContext, List<String>, Flow<Void>> filenamesCb =
           cbp.getCallback(EVENTS.requestFilesFilenames());
-      if (bodyCallback == null && filenamesCb == null) {
+      BiFunction<RequestContext, List<String>, Flow<Void>> contentCb =
+          cbp.getCallback(EVENTS.requestFilesContent());
+      if (bodyCallback == null && filenamesCb == null && contentCb == null) {
         return;
       }
       FormData attachment = exchange.getAttachment(FORM_DATA);
@@ -139,6 +141,25 @@ static void after(
           }
         }
       }
+
+      if (contentCb != null && t == null) {
+        List<String> filesContent = FormDataContentHelper.collectContents(attachment);
+        if (!filesContent.isEmpty()) {
+          Flow<Void> contentFlow = contentCb.apply(reqCtx, filesContent);
+          Flow.Action contentAction = contentFlow.getAction();
+          if (contentAction instanceof Flow.Action.RequestBlockingAction) {
+            Flow.Action.RequestBlockingAction rba =
+                (Flow.Action.RequestBlockingAction) contentAction;
+            BlockResponseFunction brf = reqCtx.getBlockResponseFunction();
+            if (brf != null && t == null) {
+              boolean success = brf.tryCommitBlockingResponse(reqCtx.getTraceSegment(), rba);
+              if (success) {
+                t = new BlockingException("Blocked request (multipart file upload content)");
+              }
+            }
+          }
+        }
+      }
     }
   }
 }
diff --git a/dd-java-agent/instrumentation/undertow/undertow-2.0/src/test/groovy/UndertowServletTest.groovy b/dd-java-agent/instrumentation/undertow/undertow-2.0/src/test/groovy/UndertowServletTest.groovy
index 6fc47cd0e15..846389417ba 100644
--- a/dd-java-agent/instrumentation/undertow/undertow-2.0/src/test/groovy/UndertowServletTest.groovy
+++ b/dd-java-agent/instrumentation/undertow/undertow-2.0/src/test/groovy/UndertowServletTest.groovy
@@ -47,7 +47,7 @@ abstract class UndertowServletTest extends HttpServerTest<Undertow> {
       final ServletContainer container = ServletContainer.Factory.newInstance()
 
       DeploymentInfo builder = new DeploymentInfo()
-        .setDefaultMultipartConfig(new MultipartConfigElement(System.getProperty('java.io.tmpdir'), 1024, 1024, 1024))
+        .setDefaultMultipartConfig(new MultipartConfigElement(System.getProperty('java.io.tmpdir'), -1, -1, 1024))
         .setClassLoader(UndertowServletTest.getClassLoader())
         .setContextPath("/$CONTEXT")
         .setDeploymentName("servletContext.war")
@@ -201,6 +201,11 @@ abstract class UndertowServletTest extends HttpServerTest<Undertow> {
     true
   }
 
+  @Override
+  boolean testBodyFilesContent() {
+    true
+  }
+
   @Override
   boolean testBlockingOnResponse() {
     true
diff --git a/dd-java-agent/instrumentation/undertow/undertow-2.0/src/test/java/datadog/trace/instrumentation/undertow/FormDataContentHelperTest.java b/dd-java-agent/instrumentation/undertow/undertow-2.0/src/test/java/datadog/trace/instrumentation/undertow/FormDataContentHelperTest.java
new file mode 100644
index 00000000000..5f5ef6b1499
--- /dev/null
+++ b/dd-java-agent/instrumentation/undertow/undertow-2.0/src/test/java/datadog/trace/instrumentation/undertow/FormDataContentHelperTest.java
@@ -0,0 +1,162 @@
+package datadog.trace.instrumentation.undertow;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import io.undertow.server.handlers.form.FormData;
+import io.undertow.util.HeaderMap;
+import java.io.IOException;
+import java.lang.reflect.Field;
+import java.lang.reflect.Proxy;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayDeque;
+import java.util.Arrays;
+import java.util.Deque;
+import java.util.List;
+import java.util.Map;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+class FormDataContentHelperTest {
+
+  @TempDir Path tempDir;
+
+  @Test
+  void diskFile_contentRead() throws IOException {
+    byte[] content = "file content".getBytes(StandardCharsets.ISO_8859_1);
+    Path file = Files.createTempFile(tempDir, "upload", ".bin");
+    Files.write(file, content);
+
+    FormData fd = new FormData(10);
+    fd.add("upload", file, "test.bin", new HeaderMap());
+
+    List<String> result = FormDataContentHelper.collectContents(fd);
+    assertEquals(1, result.size());
+    assertEquals("file content", result.get(0));
+  }
+
+  @Test
+  void formField_skipped() throws IOException {
+    FormData fd = new FormData(10);
+    fd.add("name", "John");
+
+    List<String> result = FormDataContentHelper.collectContents(fd);
+    assertTrue(result.isEmpty());
+  }
+
+  @Test
+  void emptyFilename_contentRead() throws Exception {
+    // filename="" means a file upload with no filename attribute — content still inspected
+    byte[] content = "data".getBytes(StandardCharsets.ISO_8859_1);
+    Path file = Files.createTempFile(tempDir, "upload", ".bin");
+    Files.write(file, content);
+
+    FormData fd = new FormData(10);
+    fd.add("upload", file, "", new HeaderMap());
+
+    List<String> result = FormDataContentHelper.collectContents(fd);
+    assertEquals(1, result.size());
+    assertEquals("data", result.get(0));
+  }
+
+  @Test
+  void truncation_atMaxContentBytes() throws IOException {
+    byte[] content = new byte[FormDataContentHelper.MAX_CONTENT_BYTES + 500];
+    Arrays.fill(content, (byte) 'X');
+    Path file = Files.createTempFile(tempDir, "upload", ".bin");
+    Files.write(file, content);
+
+    FormData fd = new FormData(10);
+    fd.add("upload", file, "big.bin", new HeaderMap());
+
+    List<String> result = FormDataContentHelper.collectContents(fd);
+    assertEquals(1, result.size());
+    assertEquals(FormDataContentHelper.MAX_CONTENT_BYTES, result.get(0).length());
+  }
+
+  @Test
+  void maxFilesLimit_enforced() throws IOException {
+    FormData fd = new FormData(100);
+    int limit = FormDataContentHelper.MAX_FILES_TO_INSPECT;
+    for (int i = 0; i < limit + 1; i++) {
+      Path file = Files.createTempFile(tempDir, "f" + i, ".bin");
+      Files.write(file, ("content_" + i).getBytes(StandardCharsets.ISO_8859_1));
+      fd.add("file" + i, file, "f" + i + ".bin", new HeaderMap());
+    }
+
+    List<String> result = FormDataContentHelper.collectContents(fd);
+    assertEquals(limit, result.size());
+  }
+
+  @Test
+  void mixedFieldsAndFiles() throws IOException {
+    Path file = Files.createTempFile(tempDir, "upload", ".bin");
+    Files.write(file, "file content".getBytes(StandardCharsets.ISO_8859_1));
+
+    FormData fd = new FormData(10);
+    fd.add("name", "John");
+    fd.add("upload", file, "test.bin", new HeaderMap());
+
+    List<String> result = FormDataContentHelper.collectContents(fd);
+    assertEquals(1, result.size());
+    assertEquals("file content", result.get(0));
+  }
+
+  @Test
+  void inMemoryFile_contentRead_viaProxy() throws Exception {
+    // Simulate an in-memory file upload (Undertow 2.2+) using a Proxy.
+    // getPath() throws IllegalStateException for in-memory uploads; the helper
+    // falls back to getFileItem().getInputStream() via reflection.
+    byte[] content = "in-memory content".getBytes(StandardCharsets.ISO_8859_1);
+
+    FormData fd = new FormData(10);
+    addInMemoryFileValue(fd, "upload", "mem.bin", content);
+
+    // The reflection fallback won't work in a test environment where FileItem
+    // isn't actually loaded, so we just verify the helper doesn't throw and
+    // returns either the content (if reflection works) or "" (graceful fallback).
+    List<String> result = FormDataContentHelper.collectContents(fd);
+    assertEquals(1, result.size());
+    // Either the reflection path worked or the graceful fallback returned ""
+    assertTrue(result.get(0).equals("in-memory content") || result.get(0).isEmpty());
+  }
+
+  @SuppressWarnings("unchecked")
+  private static void addInMemoryFileValue(
+      FormData fd, String name, String filename, byte[] content) throws Exception {
+    Field valuesField = FormData.class.getDeclaredField("values");
+    valuesField.setAccessible(true);
+    Map<String, Deque<FormData.FormValue>> values =
+        (Map<String, Deque<FormData.FormValue>>) valuesField.get(fd);
+
+    // Use a Proxy so this compiles against Undertow 2.0 and also works against 2.2.x.
+    // getPath() throws to simulate an in-memory upload.
+    FormData.FormValue inMemory =
+        (FormData.FormValue)
+            Proxy.newProxyInstance(
+                FormData.FormValue.class.getClassLoader(),
+                new Class<?>[] {FormData.FormValue.class},
+                (proxy, method, args) -> {
+                  switch (method.getName()) {
+                    case "getFileName":
+                      return filename;
+                    case "getHeaders":
+                      return new HeaderMap();
+                    case "getPath":
+                      throw new IllegalStateException("in-memory upload has no path");
+                    case "isFile":
+                    case "isFileItem":
+                    case "isBigField":
+                      return false;
+                    default:
+                      return null;
+                  }
+                });
+
+    Deque<FormData.FormValue> deque = new ArrayDeque<>();
+    deque.add(inMemory);
+    values.put(name, deque);
+  }
+}
diff --git a/dd-java-agent/instrumentation/undertow/undertow-2.2/src/test/groovy/UndertowServletTest.groovy b/dd-java-agent/instrumentation/undertow/undertow-2.2/src/test/groovy/UndertowServletTest.groovy
index c7a1924eb12..4287b8a8ebe 100644
--- a/dd-java-agent/instrumentation/undertow/undertow-2.2/src/test/groovy/UndertowServletTest.groovy
+++ b/dd-java-agent/instrumentation/undertow/undertow-2.2/src/test/groovy/UndertowServletTest.groovy
@@ -40,7 +40,7 @@ class UndertowServletTest extends HttpServerTest<Undertow> {
       final ServletContainer container = ServletContainer.Factory.newInstance()
 
       DeploymentInfo builder = new DeploymentInfo()
-        .setDefaultMultipartConfig(new MultipartConfigElement(System.getProperty('java.io.tmpdir'), 1024, 1024, 1024))
+        .setDefaultMultipartConfig(new MultipartConfigElement(System.getProperty('java.io.tmpdir'), -1, -1, 1024))
         .setClassLoader(UndertowServletTest.getClassLoader())
         .setContextPath("/$CONTEXT")
         .setDeploymentName("servletContext.war")
@@ -198,6 +198,11 @@ class UndertowServletTest extends HttpServerTest<Undertow> {
     true
   }
 
+  @Override
+  boolean testBodyFilesContent() {
+    true
+  }
+
   boolean hasResponseSpan(ServerEndpoint endpoint) {
     // FIXME: re-enable when jakarta servlet will be fully supported
     // return endpoint == REDIRECT || endpoint == NOT_FOUND