{"id":"USN-7927-3","summary":"python-urllib3 regression","details":"USN-7927-1 fixed vulnerabilities in urllib3. The update for CVE-2025-66471\nintroduced a regression in urllib3 when decompressing zstd data. This\nupdate fixes the problem.\n\nWe apologize for the inconvenience.\n\nOriginal advisory details:\n\n Illia Volochii discovered that urllib3 did not limit the steps in a\n decompression chain. An attacker could possibly use this issue to cause\n urllib3 to use excessive resources, causing a denial of service.\n (CVE-2025-66418)\n\n Rui Xi discovered that urllib3 incorrectly handled highly compressed data.\n An attacker could possibly use this issue to cause urllib3 to use\n excessive resources, causing a denial of service. This issue only affected\n Ubuntu 24.04 LTS, Ubuntu 25.04, and Ubuntu 25.10. (CVE-2025-66471)\n\n For the brotli encoding, the fix for CVE-2025-66471 requires an additional\n security update in the brotli package.","modified":"2026-02-10T04:50:46Z","published":"2026-01-13T14:36:44Z","related":["UBUNTU-CVE-2025-66471"],"upstream":["CVE-2025-66471","UBUNTU-CVE-2025-66471"],"references":[{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-7927-3"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2025-66471"},{"type":"REPORT","url":"https://bugs.launchpad.net/bugs/2136906"}],"affected":[{"package":{"name":"python-urllib3","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/python-urllib3@2.0.7-1ubuntu0.6?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.7-1ubuntu0.6"}]}],"versions":["1.26.16-1","1.26.18-1","2.0.7-1","2.0.7-1ubuntu0.1","2.0.7-1ubuntu0.2","2.0.7-1ubuntu0.3","2.0.7-1ubuntu0.4","2.0.7-1ubuntu0.5"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"2.0.7-1ubuntu0.6","binary_name":"python3-urllib3"}]},"database_specific":{"cves_map":{"cves":[{"id":"CVE-2025-66471","severity":[{"score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H","type":"CVSS_V4"},{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}]}],"ecosystem":"Ubuntu:24.04:LTS"},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-7927-3.json"}},{"package":{"name":"python-urllib3","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/python-urllib3@2.3.0-3ubuntu0.4?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.3.0-3ubuntu0.4"}]}],"versions":["2.3.0-2","2.3.0-2ubuntu1","2.3.0-3","2.3.0-3ubuntu0.1","2.3.0-3ubuntu0.2","2.3.0-3ubuntu0.3"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"2.3.0-3ubuntu0.4","binary_name":"python3-urllib3"}]},"database_specific":{"cves_map":{"cves":[{"id":"CVE-2025-66471","severity":[{"score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H","type":"CVSS_V4"},{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}]}],"ecosystem":"Ubuntu:25.10"},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-7927-3.json"}}],"schema_version":"1.7.3"}