Home / mailings

PDF

[USN-8335-1] pyOpenSSL vulnerability

Posted on 28 May 2026
Ubuntu Security

==========================================================================Ubuntu Security Notice USN-8335-1
May 28, 2026

pyopenssl vulnerability
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

pyOpenSSL could allow unintended access to network services.

Software Description:
- pyopenssl: Python wrapper around the OpenSSL library

Details:

It was discovered that pyOpenSSL incorrectly handled exceptions in the
tlsext_servername callback. This could result in connections being accepted
after an exception, contrary to expectations.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 20.04 LTS
python-openssl 19.0.0-1ubuntu0.1~esm1
Available with Ubuntu Pro
python3-openssl 19.0.0-1ubuntu0.1~esm1
Available with Ubuntu Pro

Ubuntu 18.04 LTS
python-openssl 17.5.0-1ubuntu1+esm1
Available with Ubuntu Pro
python3-openssl 17.5.0-1ubuntu1+esm1
Available with Ubuntu Pro

Ubuntu 16.04 LTS
python-openssl 0.15.1-2ubuntu0.2+esm1
Available with Ubuntu Pro
python3-openssl 0.15.1-2ubuntu0.2+esm1
Available with Ubuntu Pro

In general, a standard system update will make all the necessary changes.

References:
https://ubuntu.com/security/notices/USN-8335-1
CVE-2026-27448

--===============1461786779044724690==Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature

 

TOP