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Ubuntu Security Notice USN-7975-1
January 22, 2026

pyasn1 vulnerability
==========================================================================

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

- Ubuntu 25.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS

Summary:

pyasn1 could be made to crash if it received specially crafted input.

Software Description:
- pyasn1: ASN.1 library for Python

Details:

It was discovered that pyasn1 incorrectly handled malformed RELATIVE-OIDs
with excessive continuation octets. An attacker could possibly use this
issue to cause pyasn1 to consume memory, leading to a denial of service.

Update instructions:

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

Ubuntu 25.10
  python3-pyasn1                  0.6.1-1ubuntu0.1

Ubuntu 24.04 LTS
  python3-pyasn1                  0.4.8-4ubuntu0.1

Ubuntu 22.04 LTS
  python3-pyasn1                  0.4.8-1ubuntu0.1

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

References:
  https://ubuntu.com/security/notices/USN-7975-1
  CVE-2026-23490

Package Information:
  https://launchpad.net/ubuntu/+source/pyasn1/0.6.1-1ubuntu0.1
  https://launchpad.net/ubuntu/+source/pyasn1/0.4.8-4ubuntu0.1
  https://launchpad.net/ubuntu/+source/pyasn1/0.4.8-1ubuntu0.1