Not Failing Securely ('Failing Open') Affecting pyOpenSSL package, versions <0:26.0.0-1.1.hum1


Severity

Recommended
0.0
medium
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.04% (13th percentile)

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  • Snyk IDSNYK-RHEL10-PYOPENSSL-15994969
  • published19 Apr 2026
  • disclosed17 Mar 2026

Introduced: 17 Mar 2026

CVE-2026-27448  (opens in a new tab)
CWE-636  (opens in a new tab)

How to fix?

Upgrade RHEL:10 pyOpenSSL to version 0:26.0.0-1.1.hum1 or higher.
This issue was patched in RHSA-2026:7224.

NVD Description

Note: Versions mentioned in the description apply only to the upstream pyOpenSSL package and not the pyOpenSSL package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

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 Base Scores

version 3.1