CVE-2026-115557
Distrust compromised intermediate certificates in ssl module
At a glance
- Severity
- CRITICAL 9.4
- EPSS
- EPSS 0.53 % · percentile 45 (2026-10-27)
- State
- PUBLISHED
- Published
- Updated
- Assigner
- PSF
- NVD status
- Awaiting Analysis
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.
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | CRITICAL 9.4 | 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 | PSF |
| CVSS 4.0 | CRITICAL 9.4 | 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 | NVD · cna@python.org (Secondary) |
Weaknesses (CWE)
European references
- ENISA EUVD · EUVD-2026-109299
- GCVE · GCVE-0-2026-115557
CERT-FR advisories
- CERTFR-2026-AVI-1379 — Multiples vulnérabilités dans CPython · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| Python Software Foundation · CPython | affected 0 < 3.11.18 ; affected 3.12.0 < 3.12.16 ; affected 3.13.0 < 3.13.18 ; affected 3.14.0 < 3.14.10 ; affected 3.15.0 < 3.15.2 ; affected 3.16.0a1 < 3.16.0 |
References
- http://www.openwall.com/lists/oss-security/2026/10/20/29
- https://github.com/python/cpython/pull/160042
- https://github.com/python/cpython/issues/160040
- https://emudhra.we-have-a-problem.com/
- https://mail.python.org/archives/list/security-announce@python.org/thread/FNAJMZV6XQYLVPABNINDMF3VF66AYLW4/
- https://github.com/python/cpython/commit/21a50891ab4be2e9955239e625ae2b40c6b1854d
- https://github.com/python/cpython/commit/36cd295f32fc9ba19399e01abee91231440a41dd
- https://github.com/python/cpython/commit/48d9b2712cd52206c7a5882d0fdca4863ed65e93
- https://github.com/python/cpython/commit/7dd8b4736a1419750b94a388e6d158be15836fe6
- https://github.com/python/cpython/commit/98f0e4ed349f370dc8a00366da1a9797e11c9ed5
- https://github.com/python/cpython/commit/a17d9ef549008133eadf20689b1f4787902efe5b
- https://github.com/python/cpython/commit/af52b41afa4330fb38583db553631baa2f122f90
- https://github.com/python/cpython/commit/c7fd7edf7e0d122a3973cf676fae21b6aaa650a8
- https://github.com/python/cpython/commit/e2a9dd97ef9571c710ac0afaa834c8879aebce78
- https://github.com/python/cpython/commit/e4500d8a437ee5b988a5410cb9b59d177aa01370
- https://github.com/python/cpython/commit/e4f63e65a93cf44c14274aa987e644b8c003625e
- https://github.com/python/cpython/commit/e9bf2cf84eebf838a1edaa1c648c2b36345b99d3
- http://www.openwall.com/lists/oss-security/2026/10/24/5
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |