{"id":"CVE-2026-34513","aliases":["GHSA-hcc4-c3v8-rx92","PYSEC-2026-2095"],"title":"AIOHTTP Affected by Denial of Service (DoS) via Unbounded DNS Cache in TCPConnector","summary":"AIOHTTP Affected by Denial of Service (DoS) via Unbounded DNS Cache in TCPConnector","severity":"low","vendor":"aiohttp","product":"aiohttp","ecosystem":"pip","affected":["aiohttp < 3.13.4"],"patched":["aiohttp 3.13.4"],"published":"2026-04-01","updated":"2026-09-10","sourceUpdated":"2026-09-10T03:51:02.067006429Z","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-hcc4-c3v8-rx92","references":[{"url":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-hcc4-c3v8-rx92"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34513"},{"url":"https://github.com/aio-libs/aiohttp/commit/c4d77c3533122be353b8afca8e8675e3b4cbda98"},{"url":"https://github.com/aio-libs/aiohttp"},{"url":"https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4"}],"tags":["osv","pip"],"epss":0.0044,"epssPercentile":0.37698,"ingestedAt":"2026-07-13T18:57:59.110Z","slug":"CVE-2026-34513","body":"## Overview\n\n### 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\n\n## Affected packages\n\n- `aiohttp < 3.13.4`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `aiohttp 3.13.4`","depth":"sunlit","depthScore":14,"depthScoreParts":{"impact":13.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}