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.

CVSS 4.0

9.4CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

EPSS

0.5% chance of exploitation in the next 30 days; higher than 44% of CVEs (scores of 2026-10-25)

CWE

CWE-299

Published

2026-10-24

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

References

• http://www.openwall.com/lists/oss-security/2026/10/20/29
• https://emudhra.we-have-a-problem.com/
• https://github.com/python/cpython/commit/21a50891ab4be2e9955239e625ae2b40c6b1854d
• https://github.com/python/cpython/commit/36cd295f32fc9ba19399e01abee91231440a41dd
• https://github.com/python/cpython/commit/48d9b2712cd52206c7a5882d0fdca4863ed65e93

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