---
id: "CVE-2026-122233"
kind: "vulnerability"
aliases: ["CVE-2026-122233"]
title: "FrankenPHP: worker mode leaks earlier requests' HTTP response headers to other users"
severity: "medium"
cvss: 6.3
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["frankenphp", "php", "runtime", "self-hosted", "worker-mode"]
not_affected_if: ["default-config", "no-http-get-last-response-headers"]
published_at: "2026-11-04T21:18:10+00:00"
first_seen_at: "2026-11-04T21:49:21+00:00"
updated_at: "2026-11-04T21:51:10+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-122233", "first_seen_at": "2026-11-04T21:49:21+00:00"}]
exploit_sources: []
---

# FrankenPHP: worker mode leaks earlier requests' HTTP response headers to other users

FrankenPHP before 1.13.4 does not clear the last HTTP response headers between requests in worker mode, so a later request can read headers fetched by an earlier request on the same worker thread. An attacker can thereby see other users' Set-Cookie or token headers returned by backend APIs.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the FrankenPHP version with `frankenphp version` and compare it against `1.13.4`.
- Check whether worker mode is enabled in the server configuration.
- Check whether application code calls `http_get_last_response_headers()`.

## Fix

- FrankenPHP: upgrade to `1.13.4` or later.

## Timeline

- 2026-11-04T21:49:21+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-122233

## Documents

- [advisory] Vendor advisory: github.com https://github.com/php/frankenphp/security/advisories/GHSA-pmvg-8483-mw84
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/frankenphp-before-1.13.4-cross-request-response-header-leak-in-worker-mode
- [fix] Patch: github.com https://github.com/php/frankenphp/commit/3fade63bb1c1d246926ed8a00520015f94cdc819
- [fix] Release notes: github.com https://github.com/php/frankenphp/releases/tag/v1.13.4

## From the sources

FrankenPHP before 1.13.4 contains an information disclosure vulnerability in worker mode that fails to clear last HTTP stream response headers between requests, because the reset only happens in RSHUTDOWN, which worker requests skip. Later requests calling http_get_last_response_headers() can read headers fetched by earlier requests on the same worker thread, exposing other users' Set-Cookie or token headers from backend APIs.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_