{"id":"UBUNTU-CVE-2026-27171","details":"zlib before 1.3.2 allows CPU consumption via crc32_combine64 and crc32_combine_gen64 because x2nmodp can do right shifts within a loop that has no termination condition.","modified":"2026-09-01T15:45:22.746663516Z","published":"2026-02-18T04:16:00Z","related":["USN-8706-1"],"upstream":["CVE-2026-27171"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-27171"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8706-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-27171"},{"type":"REPORT","url":"https://7asecurity.com/blog/2026/02/zlib-7asecurity-audit/"},{"type":"REPORT","url":"https://7asecurity.com/reports/pentest-report-zlib-RC1.1.pdf"},{"type":"REPORT","url":"https://github.com/madler/zlib/releases/tag/v1.3.2"},{"type":"REPORT","url":"https://ostif.org/zlib-audit-complete/"}],"affected":[{"package":{"name":"zlib","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/zlib?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:1.3.dfsg-3.1ubuntu2.2"}]}],"versions":["1:1.2.13.dfsg-1ubuntu5","1:1.3.dfsg-3ubuntu1","1:1.3.dfsg-3.1ubuntu1","1:1.3.dfsg-3.1ubuntu2","1:1.3.dfsg-3.1ubuntu2.1"],"ecosystem_specific":{"priority_reason":"Resource consumption via API misuse only","binaries":[{"binary_name":"lib32z1","binary_version":"1:1.3.dfsg-3.1ubuntu2.2"},{"binary_name":"lib64z1","binary_version":"1:1.3.dfsg-3.1ubuntu2.2"},{"binary_version":"1:1.3.dfsg-3.1ubuntu2.2","binary_name":"libminizip1t64"},{"binary_name":"libx32z1","binary_version":"1:1.3.dfsg-3.1ubuntu2.2"},{"binary_version":"1:1.3.dfsg-3.1ubuntu2.2","binary_name":"minizip"},{"binary_name":"zlib1g","binary_version":"1:1.3.dfsg-3.1ubuntu2.2"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27171.json"}},{"package":{"name":"zlib","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/zlib?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:1.3.dfsg+really1.3.1-1ubuntu1","1:1.3.dfsg+really1.3.1-1ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_name":"lib32z1","binary_version":"1:1.3.dfsg+really1.3.1-1ubuntu2"},{"binary_name":"lib64z1","binary_version":"1:1.3.dfsg+really1.3.1-1ubuntu2"},{"binary_name":"libminizip1t64","binary_version":"1:1.3.dfsg+really1.3.1-1ubuntu2"},{"binary_name":"libx32z1","binary_version":"1:1.3.dfsg+really1.3.1-1ubuntu2"},{"binary_name":"minizip","binary_version":"1:1.3.dfsg+really1.3.1-1ubuntu2"},{"binary_version":"1:1.3.dfsg+really1.3.1-1ubuntu2","binary_name":"zlib1g"}],"priority_reason":"Resource consumption via API misuse only"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27171.json"}},{"package":{"name":"zlib","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/zlib?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:1.3.dfsg+really1.3.1-1ubuntu3.1"}]}],"versions":["1:1.3.dfsg+really1.3.1-1ubuntu2","1:1.3.dfsg+really1.3.1-1ubuntu3"],"ecosystem_specific":{"binaries":[{"binary_name":"lib32z1","binary_version":"1:1.3.dfsg+really1.3.1-1ubuntu3.1"},{"binary_name":"lib64z1","binary_version":"1:1.3.dfsg+really1.3.1-1ubuntu3.1"},{"binary_name":"libminizip1t64","binary_version":"1:1.3.dfsg+really1.3.1-1ubuntu3.1"},{"binary_name":"libx32z1","binary_version":"1:1.3.dfsg+really1.3.1-1ubuntu3.1"},{"binary_name":"minizip","binary_version":"1:1.3.dfsg+really1.3.1-1ubuntu3.1"},{"binary_name":"zlib1g","binary_version":"1:1.3.dfsg+really1.3.1-1ubuntu3.1"}],"availability":"No subscription required","priority_reason":"Resource consumption via API misuse only"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27171.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"low"}]}