CVE-2026-34518
MEDIUM5.3EPSS 0.01%AIOHTTP leaks Cookie and Proxy-Authorization headers on cross-origin redirect
Published: 4/1/2026Modified: 5/5/2026
Description
### 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
Affected packages (2)
- Debian/python-aiohttpfrom 0
- PyPI/aiohttpfrom 0, < 3.13.4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U |
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
References (6)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-34518
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-34518
- PATCHhttps://github.com/aio-libs/aiohttp
- WEBhttps://github.com/aio-libs/aiohttp/commit/5351c980dcec7ad385730efdf4e1f4338b24fdb6
- WEBhttps://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
- WEBhttps://github.com/aio-libs/aiohttp/security/advisories/GHSA-966j-vmvw-g2g9