CVE-2026-115557: critical vulnerability in Python Software Foundation CPython
Distrust compromised intermediate certificates in ssl module
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.4epss 0.5%
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.
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
Affected products
Python Software Foundation · CPythonRelated CVEs — Python Software Foundation CPython
In the same product, most dangerous first.
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References
https://emudhra.we-have-a-problem.com/https://github.com/python/cpython/commit/21a50891ab4be2e9955239e625ae2b40c6b1854dhttps://github.com/python/cpython/commit/36cd295f32fc9ba19399e01abee91231440a41ddhttps://github.com/python/cpython/commit/48d9b2712cd52206c7a5882d0fdca4863ed65e93https://github.com/python/cpython/commit/7dd8b4736a1419750b94a388e6d158be15836fe6https://github.com/python/cpython/commit/98f0e4ed349f370dc8a00366da1a9797e11c9ed5https://github.com/python/cpython/commit/a17d9ef549008133eadf20689b1f4787902efe5bhttps://github.com/python/cpython/commit/af52b41afa4330fb38583db553631baa2f122f90https://github.com/python/cpython/commit/c7fd7edf7e0d122a3973cf676fae21b6aaa650a8https://github.com/python/cpython/commit/e2a9dd97ef9571c710ac0afaa834c8879aebce78https://github.com/python/cpython/commit/e4500d8a437ee5b988a5410cb9b59d177aa01370https://github.com/python/cpython/commit/e4f63e65a93cf44c14274aa987e644b8c003625e