MEDIUM 5.3

GHSA-966j-vmvw-g2g9

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

Details

### 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.

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Patch: https://github.com/aio-libs/aiohttp/commit/5351c980dcec7ad385730efdf4e1f4338b24fdb6

Are you affected?

Enter the version of the package you're using.

Affected packages

PyPI / aiohttp

Introduced in: 0 Fixed in: 3.13.4

Fix pip install --upgrade 'aiohttp>=3.13.4'

References

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]