{"id":"UBUNTU-CVE-2026-116579","details":"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.","modified":"2026-10-28T20:15:58.318257939Z","published":"2026-10-26T21:18:00Z","upstream":["CVE-2026-116579"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-116579"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-116579"},{"type":"REPORT","url":"https://github.com/crossbario/autobahn-python/security/advisories/GHSA-pjh6-c8mg-3x7m"},{"type":"REPORT","url":"https://github.com/crossbario/autobahn-python/pull/1987"},{"type":"REPORT","url":"https://github.com/crossbario/autobahn-python/commit/a41442bbee4f6126a8ce1bb892840124c24d16f1"},{"type":"REPORT","url":"https://github.com/crossbario/autobahn-python/releases/tag/v26_10_1"}],"affected":[{"package":{"name":"python-autobahn","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/python-autobahn?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.10.3+dfsg1-2","0.10.3+dfsg1-3","0.10.3+dfsg1-5"],"ecosystem_specific":{"binaries":[{"binary_name":"python-autobahn","binary_version":"0.10.3+dfsg1-5"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116579.json"}},{"package":{"name":"python-autobahn","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/python-autobahn?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.14.1+dfsg1-2ubuntu1","17.10.1+dfsg1-2"],"ecosystem_specific":{"binaries":[{"binary_name":"python-autobahn","binary_version":"17.10.1+dfsg1-2"},{"binary_name":"python3-autobahn","binary_version":"17.10.1+dfsg1-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116579.json"}},{"package":{"name":"python-autobahn","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/python-autobahn?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["17.10.1+dfsg1-5","17.10.1+dfsg1-6"],"ecosystem_specific":{"binaries":[{"binary_version":"17.10.1+dfsg1-6","binary_name":"python3-autobahn"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116579.json"}},{"package":{"name":"python-autobahn","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/python-autobahn?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["17.10.1+dfsg1-7","21.11.1+dfsg1-2","21.11.1+dfsg1-2build1"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-autobahn","binary_version":"21.11.1+dfsg1-2build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116579.json"}},{"package":{"name":"python-autobahn","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/python-autobahn?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["22.7.1+dfsg1-3","22.7.1+dfsg1-4"],"ecosystem_specific":{"binaries":[{"binary_version":"22.7.1+dfsg1-4","binary_name":"python3-autobahn"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116579.json"}},{"package":{"name":"python-autobahn","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/python-autobahn?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["24.4.2+dfsg1-5"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-autobahn","binary_version":"24.4.2+dfsg1-5"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116579.json"}},{"package":{"name":"python-autobahn","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/python-autobahn?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["23.1.2+dfsg1-2","24.4.2+dfsg1-4","24.4.2+dfsg1-5"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-autobahn","binary_version":"24.4.2+dfsg1-5"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116579.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}