PatchTheCVECVE-2026-115557: Python has added a denylist for known compromised certificates to the "ssl" module to ensure user safety even
CVE-2026-115557 is a critical-severity flaw (CVSS 9.4) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- Critical severity
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.4 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | Passive |
| EPSS exploit chance | n/a |
| CISA exploited list | No |
| Weakness | CWE-299 |
| Published | 2026-10-24 |
| Last modified | 2026-10-24 |
Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Advisories and coverage
Research and news
- oss-security list: [oss-security][CVE-2026-115557] Distrust compromised intermediate certificates in Python ssl module 2026-10-24
- Vulners Bulletins: CVE-2026-115557 2026-10-24
- Vulners Bulletins: CVE-2026-115557 2026-10-24
- Vulners Bulletins: CVE-2026-115557 Distrust compromised intermediate certificates in ssl module 2026-10-24
- Vulners Bulletins: CVE-2026-115557 2026-10-24
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-115557?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-115557 being exploited?
CVE-2026-115557 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-115557 affect?
CVE-2026-115557 affects affected software. Severity is critical (CVSS 9.4). 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 SSLCont
How urgent is CVE-2026-115557?
Priority 33/100. Critical severity