{"id":"CVE-2026-59881","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-59881","generatedAt":"2026-10-28T08:11:19.697Z","title":"Prior to 3.14.2, the WebSocket client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated, allowing a malicious server to cause unexpected CPU and memory consumption.","description":"AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.2, the WebSocket client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated, allowing a malicious server to cause unexpected CPU and memory consumption. This issue is fixed in version 3.14.2.","published":"2026-07-30T19:18:34.000Z","lastModified":"2026-10-23T22:10:00.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":6.9,"severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-20"],"affected":[],"epss":{"score":0.00524,"percentile":0.44223,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.52%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://github.com/aio-libs/aiohttp/releases/tag/v3.14.2","source":"security-advisories@github.com"},{"url":"https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6","source":"security-advisories@github.com"},{"url":"https://github.com/aio-libs/aiohttp/pull/12978","source":"security-advisories@github.com"},{"url":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mq44-7p77-q5h7","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-59881","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}