GHSA-966j-vmvw-g2g9

AIOHTTP leaks Cookie and Proxy-Authorization headers on cross-origin redirect

Source: GitHub Advisory Database (reviewed) Low CVE-2026-34518

Packages

Ecosystem	Package	Affected	Fixed in
PyPI	aiohttp	< 3.13.4	3.13.4

Details

As written in the advisory (Markdown source, shown as plain text).

### 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

References

External links from the advisory. They lead to third-party sites.

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-966j-vmvw-g2g9 web
https://nvd.nist.gov/vuln/detail/CVE-2026-34518 advisory
https://github.com/aio-libs/aiohttp/commit/5351c980dcec7ad385730efdf4e1f4338b24fdb6 web
https://github.com/aio-libs/aiohttp package
https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4 web