{"id":"CVE-2026-34513","aliases":["GHSA-hcc4-c3v8-rx92","PYSEC-2026-2095"],"url":"https://o3.security/vulnerability/CVE-2026-34513","summary":"AIOHTTP: Denial of Service (DoS) via Unbounded DNS Cache in TCPConnector","details":"### Summary\n\nAn unbounded DNS cache could result in excessive memory usage possibly resulting in a DoS situation.\n\n### Impact\n\nIf an application makes requests to a very large number of hosts, this could cause the DNS cache to continue growing and slowly use excessive amounts of memory.\n\n-----\n\nPatch: https://github.com/aio-libs/aiohttp/commit/c4d77c3533122be353b8afca8e8675e3b4cbda98","published":"2026-04-01T20:06:13.718Z","modified":"2026-08-12T03:51:39.145212226Z","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/c4d77c3533122be353b8afca8e8675e3b4cbda98","label":"aio-libs/aiohttp@c4d77c3"},"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-2026-34513.json"},{"type":"ADVISORY","url":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-hcc4-c3v8-rx92"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34513"},{"type":"FIX","url":"https://github.com/aio-libs/aiohttp/commit/c4d77c3533122be353b8afca8e8675e3b4cbda98"},{"type":"PACKAGE","url":"https://github.com/aio-libs/aiohttp"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:39.145212226Z"}}