DEBIAN-CVE-2026-27448

Advisory lineage Upstream: 1 Downstream: 0
Upstream
Published: 18 Mar 2026, 00:16
Last modified:11 Jul 2026, 21:00

Vulnerability Summary

Overall Risk (default)
low
21/100
CVSS Score
5.3 MEDIUM
3.1 (osv_debian)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

18 Mar 2026, 00:16
Published
Vulnerability first disclosed
11 Jul 2026, 21:00
Last Modified
Vulnerability information updated

Description

pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version 26.0.0, if a user provided callback to `set_tlsext_servername_callback` raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for any security-sensitive behavior, this could allow bypassing it. Starting in version 26.0.0, unhandled exceptions now result in rejecting the connection.

CVSS Metrics

  • v3.1MEDIUMScore: 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected Systems

  • debianpyopenssl

    all | all | all | all | < 25.0.0-1+deb13u1 | < 26.0.0-1

References (1)