CVE-2026-34518
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, when following redirects to a different origin, aiohttp drops the Authorization header, but retains the Cookie and Proxy-Authorization headers. This issue has been patched in version 3.13.4.
02 / AFFECTED SOFTWARE
Affected packages
304 explicit affected versions
304 explicit affected versions
151 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, when following redirects to a different origin, aiohttp drops the Authorization header, but retains the Cookie and Proxy-Authorization headers. This issue has been patched in version 3.13.4.
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, when following redirects to a different origin, aiohttp drops the Authorization header, but retains the Cookie and Proxy-Authorization headers. This issue has been patched in version 3.13.4.
### Summary When following redirects to a different origin, aiohttp drops the Authorization header, but retains the Cookie and Proxy-Authorization headers. ### Impact The Cookie and Proxy-Authorizations headers could contain sensitive information which may be leaked to an unintended party after following a redirect. ----- Patch: https://github.com/aio-libs/aiohttp/commit/5351c980dcec7ad385730efdf4e1f4338b24fdb6
05 / REFERENCES
Further evidence
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34518.json
- https://github.com/aio-libs/aiohttp/commit/5351c980dcec7ad385730efdf4e1f4338b24fdb6
- https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-966j-vmvw-g2g9
- https://nvd.nist.gov/vuln/detail/CVE-2026-34518
- https://github.com/aio-libs/aiohttp