Ubuntu alert USN-8023-1 (libxmltok)

From:
             
 
noreply+usn-bot@canonical.com
To:
             
 
ubuntu-security-announce@lists.ubuntu.com
Subject:
             
 
[USN-8023-1] xmltok library vulnerabilities
Date:
             
 
Wed, 11 Feb 2026 14:33:37 +0000
Message-ID:
             
 
<E1vqBHd-0007uI-M4@lists.ubuntu.com>
==========================================================================
Ubuntu Security Notice USN-8023-1
February 11, 2026

libxmltok vulnerabilities
==========================================================================

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

- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in the xmltok library.

Software Description:
- libxmltok: XML Parser Toolkit, runtime libraries

Details:

It was discovered that Expat, contained within the xmltok library, incorrectly
handled the initialization of parsers for external entities. An attacker could
possibly use this issue to cause a denial of service. (CVE-2026-24515)

It was discovered that Expat, contained within the xmltok library, incorrectly
handled integer calculations when allocating memory for XML tags. An attacker
could possibly use this issue to cause a denial of service or execute arbitrary
code. (CVE-2026-25210)

Update instructions:

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

Ubuntu 24.04 LTS
  libxmltok1t64                   1.2-4.1ubuntu2.24.0.4.1+esm4
                                  Available with Ubuntu Pro

Ubuntu 22.04 LTS
  libxmltok1                      1.2-4ubuntu0.22.04.1~esm6
                                  Available with Ubuntu Pro

Ubuntu 20.04 LTS
  libxmltok1                      1.2-4ubuntu0.20.04.1~esm6
                                  Available with Ubuntu Pro

Ubuntu 18.04 LTS
  libxmltok1                      1.2-4ubuntu0.18.04.1~esm6
                                  Available with Ubuntu Pro

Ubuntu 16.04 LTS
  libxmltok1                      1.2-3ubuntu0.16.04.1~esm5
                                  Available with Ubuntu Pro

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

References:
  https://ubuntu.com/security/notices/USN-8023-1
  CVE-2026-24515, CVE-2026-25210


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