{"cve":"CVE-2026-59881","nvd":{"published":"2026-07-30T19:18:33.597","modified":"2026-10-23T22:10:00.160","status":"Deferred","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.","cvss_v4":{"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","score":6.9},"cvss_v3":null,"cwes":["CWE-20"],"references":["http://github.com/aio-libs/aiohttp/releases/tag/v3.14.2","https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6","https://github.com/aio-libs/aiohttp/pull/12978","https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mq44-7p77-q5h7"],"products":[],"source":"nvd","synced_at":"2026-10-24T16:53:34.184483516+00:00"},"epss":{"cve":"CVE-2026-59881","score":0.00524,"percentile":0.44133,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-mq44-7p77-q5h7","url":"https://osv.dev/vulnerability/GHSA-mq44-7p77-q5h7","summary":"AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate","modified":"2026-09-10T03:51:14.489650589Z","packages":[{"ecosystem":"PyPI","name":"aiohttp","purl":"pkg:pypi/aiohttp","ranges":["<3.14.2"],"fixed":["3.14.2"]}]},{"id":"PYSEC-2026-3547","url":"https://osv.dev/vulnerability/PYSEC-2026-3547","summary":"AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate","modified":"2026-08-04T14:30:14.644343094Z","packages":[{"ecosystem":"PyPI","name":"aiohttp","purl":"pkg:pypi/aiohttp","ranges":["<3.14.2"],"fixed":["3.14.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}