CVE-2026-115557
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.
Executive briefing
The source record describes: 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. The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.
Evidence confidence: Limited Evidence-derived, not an exploitability verdict
Severity & attack characteristics
CVSS 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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Technical explanation & impact
The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.
Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.
Weakness classification
CWE-299Affected products and versions
NVD has not supplied machine-readable vulnerable CPE product/version entries for this CVE. This is an information gap, not proof that no products are affected. Check the vendor advisory references below.
Remediation & validation
- Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
- Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
- Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
- Validate the remediation with a version check and vulnerability rescan, then retain change evidence.
No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.
Vendor advisories, patches & exploit references
- http://www.openwall.com/lists/oss-security/2026/10/20/29 REFERENCE cna@python.org
- https://emudhra.we-have-a-problem.com/ REFERENCE cna@python.org
- https://github.com/python/cpython/commit/21a50891ab4be2e9955239e625ae2b40c6b1854d VENDOR cna@python.org
- https://github.com/python/cpython/commit/36cd295f32fc9ba19399e01abee91231440a41dd VENDOR cna@python.org
- https://github.com/python/cpython/commit/48d9b2712cd52206c7a5882d0fdca4863ed65e93 VENDOR cna@python.org
- https://github.com/python/cpython/commit/7dd8b4736a1419750b94a388e6d158be15836fe6 VENDOR cna@python.org
- https://github.com/python/cpython/commit/98f0e4ed349f370dc8a00366da1a9797e11c9ed5 VENDOR cna@python.org
- https://github.com/python/cpython/commit/a17d9ef549008133eadf20689b1f4787902efe5b VENDOR cna@python.org
- https://github.com/python/cpython/commit/af52b41afa4330fb38583db553631baa2f122f90 VENDOR cna@python.org
- https://github.com/python/cpython/commit/c7fd7edf7e0d122a3973cf676fae21b6aaa650a8 VENDOR cna@python.org
- https://github.com/python/cpython/commit/e2a9dd97ef9571c710ac0afaa834c8879aebce78 VENDOR cna@python.org
- https://github.com/python/cpython/commit/e4500d8a437ee5b988a5410cb9b59d177aa01370 VENDOR cna@python.org
- https://github.com/python/cpython/commit/e4f63e65a93cf44c14274aa987e644b8c003625e VENDOR cna@python.org
- https://github.com/python/cpython/commit/e9bf2cf84eebf838a1edaa1c648c2b36345b99d3 VENDOR cna@python.org
- https://github.com/python/cpython/issues/160040 VENDOR cna@python.org
- https://github.com/python/cpython/pull/160042 VENDOR cna@python.org
- https://mail.python.org/archives/list/security-announce@python.org/thread/FNAJMZV6XQYLVPABNINDMF3VF66AYLW4/ REFERENCE cna@python.org
- http://www.openwall.com/lists/oss-security/2026/10/24/5 REFERENCE af854a3a-2127-422b-91ae-364da2661108
Information gaps & confidence notes
These gaps indicate missing source data. CVE Watch does not fill them with guessed product, exploit or patch details.
- NVD does not currently provide machine-readable vulnerable CPE product/version entries for this record.
Last enrichment: 2026-11-03T14:03:11+00:00 · Source last modified: 2026-11-02T15:17:15.000