CVE-2026-115557
Critical
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.
SeverityCritical
CVSS9.4
Exploit probability—
ProductCPython
PublishedOct 24, 2026
First seenOct 24, 2026
Weakness typeCWE-299CWE-299
How to fix
Update
- Python Software Foundation CPython3.11.18, 3.12.16, 3.13.18, 3.14.10, 3.15.2, 3.16.0 or later
Patches
- github.com/python/cpython/pull/160042
- github.com/python/cpython/commit/21a50891ab4be2e9955239e625ae2b40c6b1854d
- github.com/python/cpython/commit/36cd295f32fc9ba19399e01abee91231440a41dd
- github.com/python/cpython/commit/48d9b2712cd52206c7a5882d0fdca4863ed65e93
- github.com/python/cpython/commit/7dd8b4736a1419750b94a388e6d158be15836fe6
- github.com/python/cpython/commit/98f0e4ed349f370dc8a00366da1a9797e11c9ed5
- github.com/python/cpython/commit/a17d9ef549008133eadf20689b1f4787902efe5b
- github.com/python/cpython/commit/af52b41afa4330fb38583db553631baa2f122f90
- github.com/python/cpython/commit/c7fd7edf7e0d122a3973cf676fae21b6aaa650a8
- github.com/python/cpython/commit/e2a9dd97ef9571c710ac0afaa834c8879aebce78
- github.com/python/cpython/commit/e4500d8a437ee5b988a5410cb9b59d177aa01370
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Python Software Foundation CPython | v < 3.11.18, 3.12.0 ≤ v < 3.12.16, 3.13.0 ≤ v < 3.13.18, 3.14.0 ≤ v < 3.14.10, 3.15.0 ≤ v < 3.15.2, 3.16.0a1 ≤ v < 3.16.0 | 3.11.18, 3.12.16, 3.13.18, 3.14.10, 3.15.2, 3.16.0 |
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