{"id":"CVE-2026-115557","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-115557","generatedAt":"2026-10-27T23:51:20.161Z","title":"Python has added a denylist for known compromised certificates to the \"ssl\" module to ensure user safety even without certificate revocation configured.","description":"Python has added a denylist for known compromised certificates to the \"ssl\" module to ensure user safety even without certificate revocation configured. Known compromised certificates will automatically be rejected regardless of the SSLContext policy configuration.","published":"2026-10-24T15:17:34.000Z","lastModified":"2026-10-27T01:19:06.000Z","status":"Awaiting Analysis","sourceIdentifier":"cna@python.org","cvss":{"version":"4.0","score":9.4,"severity":"CRITICAL","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-299"],"affected":[],"epss":{"score":0.00534,"percentile":0.44836,"date":"2026-10-26","history":[{"date":"2026-10-25","score":0.00534,"percentile":0.44815}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.53%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-24T15:17:34.000Z","detail":{"score":"9.4","severity":"CRITICAL","publishedAt":"2026-10-24T15:17:33.600Z"},"summary":"New CVE, critical severity (CVSS 9.4)."}],"references":[{"url":"http://www.openwall.com/lists/oss-security/2026/10/20/29","source":"cna@python.org"},{"url":"https://emudhra.we-have-a-problem.com/","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/21a50891ab4be2e9955239e625ae2b40c6b1854d","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/36cd295f32fc9ba19399e01abee91231440a41dd","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/48d9b2712cd52206c7a5882d0fdca4863ed65e93","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/7dd8b4736a1419750b94a388e6d158be15836fe6","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/98f0e4ed349f370dc8a00366da1a9797e11c9ed5","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/a17d9ef549008133eadf20689b1f4787902efe5b","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/af52b41afa4330fb38583db553631baa2f122f90","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/c7fd7edf7e0d122a3973cf676fae21b6aaa650a8","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/e2a9dd97ef9571c710ac0afaa834c8879aebce78","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/e4500d8a437ee5b988a5410cb9b59d177aa01370","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/e4f63e65a93cf44c14274aa987e644b8c003625e","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/e9bf2cf84eebf838a1edaa1c648c2b36345b99d3","source":"cna@python.org"},{"url":"https://github.com/python/cpython/issues/160040","source":"cna@python.org"},{"url":"https://github.com/python/cpython/pull/160042","source":"cna@python.org"},{"url":"https://mail.python.org/archives/list/security-announce@python.org/thread/FNAJMZV6XQYLVPABNINDMF3VF66AYLW4/","source":"cna@python.org"},{"url":"http://www.openwall.com/lists/oss-security/2026/10/24/5","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-115557","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."}