Ubuntu alert USN-8251-1 (libpng1.6)

From:
             
 
noreply+usn-bot@canonical.com
To:
             
 
ubuntu-security-announce@lists.ubuntu.com
Subject:
             
 
[USN-8251-1] libpng vulnerabilities
Date:
             
 
Thu, 07 May 2026 14:07:00 +0000
Message-ID:
             
 
<E1wKzNU-00006W-3s@lists.ubuntu.com>
==========================================================================
Ubuntu Security Notice USN-8251-1
May 07, 2026

libpng1.6 vulnerabilities
==========================================================================

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

- Ubuntu 25.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS

Summary:

Several security issues were fixed in libpng.

Software Description:
- libpng1.6: PNG (Portable Network Graphics) file library

Details:

It was discovered that libpng incorrectly handled memory when processing
certain PNG files. If a user or automated system were tricked into opening
a specially crafted PNG file, an attacker could use this issue to cause
libpng to crash, resulting in a denial of service, or possibly execute
arbitrary code. (CVE-2026-33416)

It was discovered that libpng incorrectly handled expanding 8-bit paletted
rows to RGB or RGBA on ARM processors. If a user or automated system were
tricked into opening a specially crafted PNG file, an attacker could use
this issue to cause libpng to crash, resulting in a denial of service, or
possibly execute arbitrary code. (CVE-2026-33636)

It was discovered that libpng incorrectly handled certain setter APIs. An
attacker could possibly use this issue to obtain sensitive information.
(CVE-2026-34757)

Update instructions:

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

Ubuntu 25.10
  libpng16-16t64                  1.6.50-1ubuntu0.5

Ubuntu 24.04 LTS
  libpng16-16t64                  1.6.43-5ubuntu0.6

Ubuntu 22.04 LTS
  libpng16-16                     1.6.37-3ubuntu0.5

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

References:
  https://ubuntu.com/security/notices/USN-8251-1
  CVE-2026-33416, CVE-2026-33636, CVE-2026-34757

Package Information:
  https://launchpad.net/ubuntu/+source/libpng1.6/1.6.50-1ub...
  https://launchpad.net/ubuntu/+source/libpng1.6/1.6.43-5ub...
  https://launchpad.net/ubuntu/+source/libpng1.6/1.6.37-3ub...


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