diff --git a/apps/sim/executor/execution/block-executor.test.ts b/apps/sim/executor/execution/block-executor.test.ts
index 250542ee7be..6e862dc2a29 100644
--- a/apps/sim/executor/execution/block-executor.test.ts
+++ b/apps/sim/executor/execution/block-executor.test.ts
@@ -94,6 +94,53 @@ describe('BlockExecutor', () => {
     mockUploadFile.mockImplementation(async ({ customKey }) => ({ key: customKey }))
   })
 
+  it.each([false, true])(
+    'redacts header diagnostics while preserving execution values (stringified: %s)',
+    async (stringified) => {
+      const headers = [
+        { cells: { Key: 'aUtHoRiZaTiOn', Value: 'synthetic-header-value' } },
+        { cells: { Key: 'Accept', Value: 'application/json' } },
+      ]
+      const block = createBlock()
+      block.metadata = { id: BlockType.API, name: 'API' }
+      block.config.params = { headers: stringified ? JSON.stringify(headers) : headers }
+      const originalBlock = structuredClone(block)
+      const workflow: SerializedWorkflow = {
+        version: '1',
+        blocks: [block],
+        connections: [],
+        loops: {},
+        parallels: {},
+      }
+      const state = new ExecutionState()
+      const resolver = new VariableResolver(workflow, {}, state)
+      const onBlockComplete = vi.fn(async () => {})
+      const handler: BlockHandler = {
+        canHandle: () => true,
+        execute: async (_ctx, _block, inputs) => {
+          expect(inputs.headers).toEqual(block.config.params.headers)
+          return { headers }
+        },
+      }
+      const executor = new BlockExecutor([handler], resolver, { onBlockComplete }, state)
+      const ctx = createContext(state)
+
+      await executor.execute(ctx, createNode(block), block)
+      await vi.waitFor(() => expect(onBlockComplete).toHaveBeenCalledOnce())
+
+      const displayInput = {
+        headers: [
+          { cells: { Key: 'aUtHoRiZaTiOn', Value: '[REDACTED]' } },
+          { cells: { Key: 'Accept', Value: 'application/json' } },
+        ],
+      }
+      expect(ctx.blockLogs[0]?.input).toEqual(displayInput)
+      expect(onBlockComplete.mock.calls[0]?.[3]?.input).toEqual(displayInput)
+      expect(state.getBlockOutput(block.id)).toEqual({ headers })
+      expect(block).toEqual(originalBlock)
+    }
+  )
+
   it('persists function output arrays as manifests in execution state', async () => {
     const block = createBlock()
     const workflow: SerializedWorkflow = {
diff --git a/apps/sim/lib/core/security/redaction.test.ts b/apps/sim/lib/core/security/redaction.test.ts
index ac493b709ad..9b65cc66404 100644
--- a/apps/sim/lib/core/security/redaction.test.ts
+++ b/apps/sim/lib/core/security/redaction.test.ts
@@ -488,6 +488,50 @@ describe('redactSensitiveValues', () => {
 })
 
 describe('redactApiKeys', () => {
+  describe('HTTP headers', () => {
+    it.each(['aUtHoRiZaTiOn', 'Proxy-Authorization', 'X-Api-Key', 'Cookie', 'Set-Cookie'])(
+      'redacts %s in header maps and table rows without mutating the input',
+      (name) => {
+        const row = { id: 'header-row', cells: { Key: name, Value: 'synthetic-header-value' } }
+        const input = {
+          request: { headers: [row, { cells: { Key: 'Accept', Value: 'application/json' } }] },
+          responses: [
+            { headers: { [name]: 'synthetic-header-value', 'Content-Type': 'text/plain' } },
+          ],
+        }
+        const original = structuredClone(input)
+
+        const result = redactApiKeys(input)
+
+        expect(result.request.headers).toEqual([
+          { id: 'header-row', cells: { Key: name, Value: '[REDACTED]' } },
+          { cells: { Key: 'Accept', Value: 'application/json' } },
+        ])
+        expect(result.responses[0].headers).toEqual({
+          [name]: '[REDACTED]',
+          'Content-Type': 'text/plain',
+        })
+        expect(input).toEqual(original)
+        expect(redactApiKeys(result)).toEqual(result)
+      }
+    )
+
+    it('does not treat unrelated tables or cookie fields as HTTP headers', () => {
+      const input = {
+        rows: [{ cells: { Key: 'Authorization', Value: 'ordinary-table-value' } }],
+        Cookie: 'ordinary-field-value',
+        headers: [
+          null,
+          {},
+          { cells: { Key: 'Authorization' } },
+          { cells: { Key: 1, Value: 'ok' } },
+        ],
+      }
+
+      expect(redactApiKeys(input)).toEqual(input)
+    })
+  })
+
   describe('object redaction', () => {
     it.concurrent('should redact sensitive keys in flat objects', () => {
       const obj = {
diff --git a/apps/sim/lib/core/security/redaction.ts b/apps/sim/lib/core/security/redaction.ts
index af6ea2c5487..1e685470081 100644
--- a/apps/sim/lib/core/security/redaction.ts
+++ b/apps/sim/lib/core/security/redaction.ts
@@ -449,6 +449,28 @@ export function isLargeDataKey(key: string): boolean {
   return LARGE_DATA_KEYS.has(key)
 }
 
+/** Redacts supported HTTP header representations without changing the source values. */
+function redactHeaders(headers: unknown): unknown {
+  const redacted = redactApiKeys(headers)
+  const isSensitiveHeader = (name: string) =>
+    isSensitiveKey(name) || /^(?:set-)?cookie$/i.test(name)
+
+  if (Array.isArray(redacted)) {
+    for (const row of redacted) {
+      const cells = row?.cells
+      if (cells && typeof cells.Key === 'string' && isSensitiveHeader(cells.Key)) {
+        if (Object.hasOwn(cells, 'Value')) cells.Value = REDACTED_MARKER
+      }
+    }
+  } else if (redacted && typeof redacted === 'object') {
+    for (const name of Object.keys(redacted)) {
+      if (isSensitiveHeader(name)) redacted[name] = REDACTED_MARKER
+    }
+  }
+
+  return redacted
+}
+
 export function redactApiKeys(obj: any): any {
   if (obj === null || obj === undefined) {
     return obj
@@ -482,6 +504,8 @@ export function redactApiKeys(obj: any): any {
       result[key] = REDACTED_MARKER
     } else if (isLargeDataKey(key) && typeof value === 'string') {
       result[key] = TRUNCATED_MARKER
+    } else if (key.toLowerCase() === 'headers') {
+      result[key] = redactHeaders(value)
     } else if (typeof value === 'object' && value !== null) {
       result[key] = redactApiKeys(value)
     } else {