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Ubuntu Security Notice USN-8035-1
February 12, 2026

libpng1.6 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

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

Summary:

Several security issues were fixed in libpng.

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

Details:

It was discovered that the libpng simplified API incorrectly processed
palette PNG images with partial transparency and gamma correction. 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. (CVE-2025-66293)

Petr Simecek, Stanislav Fort and Pavel Kohout discovered that the libpng
simplified API incorrectly processed interlaced 16-bit PNGs with 8-bit
output format and non-minimal row strides. 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.
(CVE-2026-22695)

Cosmin Truta discovered that the libpng simplified API incorrectly handled
invalid row strides. 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. This issue only
affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2026-22801)

It was discovered that the libpng simplified API incorrectly handled
quantizing RGB images. 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. (CVE-2026-25646)

Update instructions:

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

Ubuntu 20.04 LTS
  libpng16-16                     1.6.37-2ubuntu0.1~esm2
                                  Available with Ubuntu Pro

Ubuntu 18.04 LTS
  libpng16-16                     1.6.34-1ubuntu0.18.04.2+esm2
                                  Available with Ubuntu Pro

Ubuntu 16.04 LTS
  libpng16-16                     1.6.20-2ubuntu0.1~esm3
                                  Available with Ubuntu Pro

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

References:
  https://ubuntu.com/security/notices/USN-8035-1
  CVE-2025-66293, CVE-2026-22695, CVE-2026-22801, CVE-2026-25646