Improper handling of exceptional conditions in pyopenssl - CVE-2026-27448

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Main Vulnerability Database Vulnerabilities #VU144224

Improper handling of exceptional conditions in pyopenssl - CVE-2026-27448

Published: August 18, 2026


Vulnerability identifier: #VU144224
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-27448
CWE-ID: CWE-755
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to bypass security-sensitive behavior.

The vulnerability exists due to improper exception handling in set_tlsext_servername_callback callbacks when handling TLS connections. A remote attacker can trigger an unhandled exception in a user-provided callback to bypass security-sensitive behavior.

Exploitation is possible only if an application relies on this callback for security-sensitive decisions.


Affected software

pyopenssl
SUSE Liberty Linux 9.6
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Desktop 12
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Manager Retail Branch Server
SUSE Manager Proxy
SUSE Manager Server
SUSE Manager Client Tools for SLE Micro
SUSE Linux Enterprise Micro
SUSE Linux Enterprise Micro for Rancher
SUSE Linux Micro
SUSE Manager Client Tools for RHEL, Liberty and Clones
SUSE Manager Client Tools for Debian
SUSE Manager Client Tools for SLE
SUSE Linux Enterprise Server for the Raspberry Pi
SUSE Linux Enterprise Server
SUSE Linux Enterprise Server for SAP Applications
SUSE Linux Enterprise Desktop
SUSE Linux Enterprise High Performance Computing
Public Cloud Module
Basesystem Module
Python 3 Module
openSUSE Leap
Ubuntu
openEuler
Anolis OS
Fedora
SUSE Manager Client Tools for Ubuntu 22.04
SUSE Manager Client Tools for Ubuntu 24.04
pyopenssl (Ubuntu package)
python-pyOpenSSL
python3-pyOpenSSL
python2-pyOpenSSL
pyOpenSSL
pyOpenSSL-help
python311-pyOpenSSL
python3-pyOpenSSL-doc
venv-salt-minion

How to mitigate CVE-2026-27448

Install security update from vendor's website.

pyopenssl - update to 26.0.0
pyopenssl (Ubuntu package) - addressed in versions 0.15.1-2ubuntu0.2+esm1, 17.5.0-1ubuntu1+esm1, 19.0.0-1ubuntu0.1~esm1, 21.0.0-1ubuntu0.1, 23.2.0-1ubuntu0.1, 25.0.0-1ubuntu0.1
python-pyOpenSSL - update to 17.1.0-4.32.1
python3-pyOpenSSL - addressed in versions 17.1.0-4.32.1, 19.0.0-150300.3.3.1, 21.0.0-150400.22.1
python2-pyOpenSSL - update to 19.0.0-150300.3.3.1
pyOpenSSL - addressed in versions 20.0.1-2, 21.0.0-3, 24.0.0-3
pyOpenSSL-help - addressed in versions 20.0.1-2, 21.0.0-3, 24.0.0-3
python2-pyOpenSSL - update to 20.0.1-2
python3-pyOpenSSL - addressed in versions 20.0.1-2, 21.0.0-3, 24.0.0-3
python311-pyOpenSSL - addressed in versions 23.2.0-150400.3.13.1, 24.0.0-2.1
python3-pyOpenSSL - update to 24.1.0-2
python3-pyOpenSSL-doc - update to 24.1.0-2
pyOpenSSL - update to 26.0.0-1.fc44
venv-salt-minion - addressed in versions 3006.0-1.76.1, 3006.0-2.31.2, 3006.0-2.49.2, 3006.0-2.80.1, 3006.0-3.95.1, 3006.0-150000.3.95.1

External References

Related Security Bulletins