diff --git a/apps/sim/app/api/help/route.ts b/apps/sim/app/api/help/route.ts
index 6fe478fe4b4..3c10f68f4d4 100644
--- a/apps/sim/app/api/help/route.ts
+++ b/apps/sim/app/api/help/route.ts
@@ -5,12 +5,26 @@ import { helpFormBodySchema } from '@/lib/api/contracts/common'
 import { validationErrorResponse } from '@/lib/api/server'
 import { getSession } from '@/lib/auth'
 import { generateRequestId } from '@/lib/core/utils/request'
+import {
+  isPayloadSizeLimitError,
+  MAX_MULTIPART_OVERHEAD_BYTES,
+  readFormDataWithLimit,
+} from '@/lib/core/utils/stream-limits'
 import { withRouteHandler } from '@/lib/core/utils/with-route-handler'
 import { sendEmail } from '@/lib/messaging/email/mailer'
 import { getFromEmailAddress, getHelpEmailAddress } from '@/lib/messaging/email/utils'
+import { MAX_WORKSPACE_FORMDATA_FILE_SIZE } from '@/lib/uploads/shared/types'
 
 const logger = createLogger('HelpAPI')
 
+/**
+ * The form can carry several image attachments with no server-side count
+ * cap, so this reuses the repo's largest existing per-request form-data
+ * bound (see files/upload route) rather than an arbitrary smaller limit
+ * that could reject a legitimate multi-image submission.
+ */
+const MAX_HELP_FORM_BYTES = MAX_WORKSPACE_FORMDATA_FILE_SIZE + MAX_MULTIPART_OVERHEAD_BYTES
+
 export const POST = withRouteHandler(async (req: NextRequest) => {
   const requestId = generateRequestId()
 
@@ -23,7 +37,10 @@ export const POST = withRouteHandler(async (req: NextRequest) => {
 
     const email = session.user.email
 
-    const formData = await req.formData()
+    const formData = await readFormDataWithLimit(req, {
+      maxBytes: MAX_HELP_FORM_BYTES,
+      label: 'Help request form data',
+    })
 
     const subject = formData.get('subject') as string
     const message = formData.get('message') as string
@@ -128,6 +145,13 @@ ${message}
       { status: 200 }
     )
   } catch (error) {
+    if (isPayloadSizeLimitError(error)) {
+      logger.warn(`[${requestId}] Help request form data too large`, { message: error.message })
+      return NextResponse.json(
+        { error: `Request body exceeds the maximum allowed size of ${MAX_HELP_FORM_BYTES} bytes` },
+        { status: 413 }
+      )
+    }
     if (error instanceof Error && error.message.includes('not configured')) {
       logger.error(`[${requestId}] Email service configuration error`, error)
       return NextResponse.json(
diff --git a/apps/sim/app/api/knowledge/[id]/documents/[documentId]/chunks/route.ts b/apps/sim/app/api/knowledge/[id]/documents/[documentId]/chunks/route.ts
index 059abee2fb6..75d9df48173 100644
--- a/apps/sim/app/api/knowledge/[id]/documents/[documentId]/chunks/route.ts
+++ b/apps/sim/app/api/knowledge/[id]/documents/[documentId]/chunks/route.ts
@@ -7,7 +7,7 @@ import {
   createChunkBodySchema,
   listKnowledgeChunksQuerySchema,
 } from '@/lib/api/contracts/knowledge'
-import { isZodError, parseRequest } from '@/lib/api/server'
+import { isZodError, parseJsonBody, parseRequest } from '@/lib/api/server'
 import { checkSessionOrInternalAuth } from '@/lib/auth/hybrid'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { withRouteHandler } from '@/lib/core/utils/with-route-handler'
@@ -103,9 +103,6 @@ export const POST = withRouteHandler(
     const { id: knowledgeBaseId, documentId } = await params
 
     try {
-      const body = await req.json()
-      const { workflowId, ...searchParams } = body
-
       const auth = await checkSessionOrInternalAuth(req, { requireWorkflowId: false })
       if (!auth.success || !auth.userId) {
         logger.warn(`[${requestId}] Authentication failed: ${auth.error || 'Unauthorized'}`)
@@ -113,7 +110,14 @@ export const POST = withRouteHandler(
       }
       const userId = auth.userId
 
+      const parsedBody = await parseJsonBody(req)
+      if (!parsedBody.success) return parsedBody.response
+      const { workflowId, ...searchParams } = parsedBody.data as Record<string, unknown>
+
       if (workflowId) {
+        if (typeof workflowId !== 'string') {
+          return NextResponse.json({ error: 'workflowId must be a string' }, { status: 400 })
+        }
         const authorization = await authorizeWorkflowByWorkspacePermission({
           workflowId,
           userId,
diff --git a/apps/sim/app/api/speech/token/route.test.ts b/apps/sim/app/api/speech/token/route.test.ts
index 8c00a1c7787..a555948c9d9 100644
--- a/apps/sim/app/api/speech/token/route.test.ts
+++ b/apps/sim/app/api/speech/token/route.test.ts
@@ -138,4 +138,13 @@ describe('POST /api/speech/token — usage attribution', () => {
       workspaceId: 'ws-1',
     })
   })
+
+  it('rejects an oversized body before any auth/billing work runs', async () => {
+    const oversizedBody = { chatId: 'x'.repeat(64 * 1024) }
+    const res = await POST(createMockRequest('POST', oversizedBody))
+
+    expect(res.status).toBe(413)
+    expect(mockGetSession).not.toHaveBeenCalled()
+    expect(mockRecordUsage).not.toHaveBeenCalled()
+  })
 })
diff --git a/apps/sim/app/api/speech/token/route.ts b/apps/sim/app/api/speech/token/route.ts
index 3ccb721366f..47a63b741dc 100644
--- a/apps/sim/app/api/speech/token/route.ts
+++ b/apps/sim/app/api/speech/token/route.ts
@@ -6,6 +6,7 @@ import { getErrorMessage } from '@sim/utils/errors'
 import { eq } from 'drizzle-orm'
 import { type NextRequest, NextResponse } from 'next/server'
 import { speechTokenBodySchema } from '@/lib/api/contracts/media/speech'
+import { parseOptionalJsonBody } from '@/lib/api/server'
 import { getSession } from '@/lib/auth'
 import { checkActorUsageLimits } from '@/lib/billing/calculations/usage-monitor'
 import { recordUsage } from '@/lib/billing/core/usage-log'
@@ -34,6 +35,13 @@ const STT_TOKEN_RATE_LIMIT = {
   refillIntervalMs: 72 * 1000,
 } as const
 
+/**
+ * This body only ever carries an optional chatId/workspaceId string, so a
+ * tight cap keeps an unauthenticated caller from forcing a large in-memory
+ * allocation before the auth checks below run.
+ */
+const MAX_SPEECH_TOKEN_BODY_BYTES = 16 * 1024
+
 function hashVoiceToken(token: string): string {
   return createHash('sha256').update(token).digest('hex')
 }
@@ -87,8 +95,9 @@ async function validateChatAuth(
 
 export const POST = withRouteHandler(async (request: NextRequest) => {
   try {
-    const rawBody = await request.json().catch(() => ({}))
-    const body = speechTokenBodySchema.safeParse(rawBody)
+    const parsedBody = await parseOptionalJsonBody(request, MAX_SPEECH_TOKEN_BODY_BYTES)
+    if (!parsedBody.success) return parsedBody.response
+    const body = speechTokenBodySchema.safeParse(parsedBody.data ?? {})
     const chatId =
       body.success && typeof body.data.chatId === 'string' ? body.data.chatId : undefined