{"id":"CVE-2026-59881","state":"PUBLISHED","title":"AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate","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.","publishedAt":"2026-07-30T17:34:32.415Z","updatedAt":"2026-07-30T18:35:40.624Z","severity":{"score":6.9,"label":"Medium","version":"4.0","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","source":"GitHub_M"},"assigner":"GitHub_M","products":["aio-libs aiohttp"],"affected":[{"vendor":"aio-libs","product":"aiohttp","versions":[{"version":"< 3.14.2","status":"affected"}]}],"references":["https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mq44-7p77-q5h7","https://github.com/aio-libs/aiohttp/pull/12978","https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6","http://github.com/aio-libs/aiohttp/releases/tag/v3.14.2"],"weaknesses":["CWE-20"],"ingestedAt":"2026-10-29T20:12:32.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/59xxx/CVE-2026-59881.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-59881","state":"PUBLISHED","datePublished":"2026-07-30T17:34:32.415Z","dateUpdated":"2026-07-30T18:35:40.624Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-07T16:40:07.982Z"},"containers":{"cna":{"title":"AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"aio-libs","product":"aiohttp","versions":[{"version":"< 3.14.2","status":"affected"}]}],"references":[{"url":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mq44-7p77-q5h7","name":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mq44-7p77-q5h7","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/aio-libs/aiohttp/pull/12978","name":"https://github.com/aio-libs/aiohttp/pull/12978","tags":["x_refsource_MISC"]},{"url":"https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6","name":"https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6","tags":["x_refsource_MISC"]},{"url":"http://github.com/aio-libs/aiohttp/releases/tag/v3.14.2","name":"http://github.com/aio-libs/aiohttp/releases/tag/v3.14.2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"LOW","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.9,"baseSeverity":"MEDIUM","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","lang":"en","description":"CWE-20: Improper Input Validation","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-30T17:34:32.415Z"},"source":{"advisory":"GHSA-mq44-7p77-q5h7","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-30T18:35:32.868187Z","id":"CVE-2026-59881","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-30T18:35:40.624Z"}}]}}}