Information disclosure in Aio-libs Aiohttp

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…

Vulnerability class: Information Disclosure

EPSS: 0.000 (2.8th percentile) — read the EPSS interpretation.

Affected products

Aio-libs Aiohttp — versions < 3.13.4

Weakness classification (CWE)

CWE-200 — Information Disclosure

References

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-966j-vmvw-g2g9 (x_refsource_CONFIRM)
https://github.com/aio-libs/aiohttp/commit/5351c980dcec7ad385730efdf4e1f4338b24fdb6 (x_refsource_MISC)
https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4 (x_refsource_MISC)