{"id":"CVE-2026-34518","aliases":["GHSA-966j-vmvw-g2g9","PYSEC-2026-2100"],"url":"https://o3.security/vulnerability/CVE-2026-34518","summary":"AIOHTTP: Cookie and Proxy-Authorization headers leaked on cross-origin redirect","details":"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.","published":"2026-04-01T20:15:22.426Z","modified":"2026-08-07T11:49:52.787255829Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"aiohttp","fixedVersion":"3.13.4"}],"fix":{"url":"https://github.com/aio-libs/aiohttp/commit/5351c980dcec7ad385730efdf4e1f4338b24fdb6","label":"aio-libs/aiohttp@5351c98"},"references":[{"type":"WEB","url":"https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34518.json"},{"type":"ADVISORY","url":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-966j-vmvw-g2g9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34518"},{"type":"FIX","url":"https://github.com/aio-libs/aiohttp/commit/5351c980dcec7ad385730efdf4e1f4338b24fdb6"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:49:52.787255829Z"}}