{"id":"CVE-2024-52303","aliases":["GHSA-27mf-ghqm-j3j8","PYSEC-2026-1096"],"title":"aiohttp has a memory leak when middleware is enabled when requesting a resource with a non-allowed method","summary":"aiohttp has a memory leak when middleware is enabled when requesting a resource with a non-allowed method","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","vendor":"aiohttp","product":"aiohttp","ecosystem":"pip","affected":["aiohttp >= 3.10.6, < 3.10.11"],"patched":["aiohttp 3.10.11"],"published":"2024-11-18","updated":"2026-09-10","sourceUpdated":"2026-09-10T03:50:20.382497140Z","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-27mf-ghqm-j3j8","references":[{"url":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-27mf-ghqm-j3j8"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2024-52303"},{"url":"https://github.com/aio-libs/aiohttp/commit/bc15db61615079d1b6327ba42c682f758fa96936"},{"url":"https://github.com/aio-libs/aiohttp"}],"tags":["osv","pip"],"epss":0.00591,"epssPercentile":0.46985,"ingestedAt":"2026-07-08T18:25:44.173Z","slug":"CVE-2024-52303","body":"## Overview\n\n### Summary\n\nA memory leak can occur when a request produces a `MatchInfoError`. This was caused by adding an entry to a cache on each request, due to the building of each `MatchInfoError` producing a unique cache entry.\n\n### Impact\n\nIf the user is making use of any middlewares with `aiohttp.web` then it is advisable to upgrade immediately.\n\nAn attacker may be able to exhaust the memory resources of a server by sending a substantial number (100,000s to millions) of such requests.\n\n-----\n\nPatch: https://github.com/aio-libs/aiohttp/commit/bc15db61615079d1b6327ba42c682f758fa96936\n\n## Affected packages\n\n- `aiohttp >= 3.10.6, < 3.10.11`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `aiohttp 3.10.11`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}