{"id":"CVE-2026-116579","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-116579","generatedAt":"2026-10-28T02:58:11.663Z","title":"An unauthenticated WebSocket client can send a small, highly compressed frame that allocates hundreds of MiB before rejection, causing memory-exhaustion denial of service on servers that enable the opt-in permessage-brotli feature through the compress…","description":"Autobahn Python is a WebSocket and WAMP implementation for Python that supports Twisted and asyncio. From 26.7.1 until 26.10.1, PerMessageBrotli.decompress_message_data in compress_brotli.py calls the Brotli decompressor without an output limit and checks maxMessagePayloadSize only after a complete frame has been inflated. An unauthenticated WebSocket client can send a small, highly compressed frame that allocates hundreds of MiB before rejection, causing memory-exhaustion denial of service on servers that enable the opt-in permessage-brotli feature through the compress extra. Deflate and bzip2 already enforce the remaining output budget and are outside this residual vulnerability. This issue is fixed in version 26.10.1.","published":"2026-10-26T21:18:15.000Z","lastModified":"2026-10-27T16:03:45.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-409","CWE-770"],"affected":[],"epss":null,"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 no EPSS score yet. Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-26T21:18:15.000Z","detail":{"score":"5.9","severity":"MEDIUM","publishedAt":"2026-10-26T21:18:15.117Z"},"summary":"New CVE, medium severity (CVSS 5.9)."}],"references":[{"url":"https://github.com/crossbario/autobahn-python/commit/a41442bbee4f6126a8ce1bb892840124c24d16f1","source":"security-advisories@github.com"},{"url":"https://github.com/crossbario/autobahn-python/pull/1987","source":"security-advisories@github.com"},{"url":"https://github.com/crossbario/autobahn-python/releases/tag/v26_10_1","source":"security-advisories@github.com"},{"url":"https://github.com/crossbario/autobahn-python/security/advisories/GHSA-pjh6-c8mg-3x7m","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-116579","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."}