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Fencer Vulns
medium 5.1

CVE-2026-34757 json

LIBPNG has a yse-after-free in png_set_PLTE, png_set_tRNS and png_set_hIST leading to corrupted chunk data and potential heap information disclosure

published 2026-04-09 7 mo ago modified 2026-10-26 13 d ago also EUVD-2026-20897 , JLSEC-2026-498

cvss
5.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From 1.0.9 to before 1.6.57, passing a pointer obtained from png_get_PLTE, png_get_tRNS, or png_get_hIST back into the corresponding setter on the same png_struct/png_info pair causes the setter to read from freed memory and copy its contents into the replacement buffer. The setter frees the internal buffer before copying from the caller-supplied pointer, which now dangles. The freed region may contain stale data (producing silently corrupted chunk metadata) or data from subsequent heap allocations (leaking unrelated heap contents into the chunk struct). This vulnerability is fixed in 1.6.57.

Patch / fix

  • julia libpng_jll 1.6.57+0
  • libpng libpng 1.6.57
  • libpng1.6 Debian 12 1.6.39-2+deb12u5
  • libpng1.6 Debian 13 1.6.48-1+deb13u5
  • libpng1.6 Debian 14 1.6.57-1

debian advisories DEBIAN-CVE-2026-34757

  • libpng1.6 Ubuntu 22.04 LTS 1.6.37-3ubuntu0.5
  • libpng1.6 Ubuntu 24.04 LTS 1.6.43-5ubuntu0.6
  • libpng1.6 Ubuntu 25.10 1.6.50-1ubuntu0.5
  • libpng Ubuntu Pro 14.04 LTS 1.2.50-1ubuntu2.14.04.3+esm2
  • libpng Ubuntu Pro 16.04 LTS 1.2.54-1ubuntu1.1+esm3
  • libpng1.6 Ubuntu Pro 16.04 LTS 1.6.20-2ubuntu0.1~esm4
  • libpng1.6 Ubuntu Pro 18.04 LTS 1.6.34-1ubuntu0.18.04.2+esm3
  • libpng1.6 Ubuntu Pro 20.04 LTS 1.6.37-2ubuntu0.1~esm3

ubuntu advisories UBUNTU-CVE-2026-34757

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libpng hummingbird 1 1.6.57-0.1.hum1
  • libpng-tools hummingbird 1 1.6.57-0.1.hum1

red hat advisories RHSA-2026:13719

  • libpng16 Linux Micro 6.1 1.6.58-slfo.1.1_1.1
  • libpng16 Linux Micro 6.0 1.6.58-1.1
  • libpng16 SLE Module for Basesystem 15 SP7 1.6.40-150600.3.20.1
  • libpng16 Linux Micro 6.2 1.6.44-160000.7.1
  • libpng16 Linux Micro 6.0 1.6.43-5.1
  • libpng16 Linux Micro 6.1 1.6.43-slfo.1.1_5.1
  • libpng16 SLES LTSS Extended Security 12 SP5 1.6.8-15.24.1
  • libpng15 SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 1.5.22-10.10.1

suse advisories SUSE-SU-2026:23514-1SUSE-SU-2026:23063-1SUSE-SU-2026:1602-1SUSE-SU-2026:1601-1SUSE-SU-2026:21239-1SUSE-SU-2026:21251-1

  • libpng12 openSUSE Tumbleweed 1.2.59-5.1
  • libpng16 openSUSE Leap 16.0 1.6.44-160000.7.1
  • libpng16 openSUSE Tumbleweed 1.6.57-1.1

opensuse advisories openSUSE-SU-2026:10640-1openSUSE-SU-2026:20593-1openSUSE-SU-2026:10564-1

  • libpng Alpine 3.24, Alpine 3.23, Alpine 3.22 +2 more 1.6.57-r0

alpine advisories ALPINE-CVE-2026-34757

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libpng Azure Linux 3.0 1.6.57-1

azure linux advisories AZL-82643

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-34757 updated cvss 4.4

libpng: libpng: Information disclosure and data corruption via use-after-free vulnerability

  • Red Hat build of OpenJDK 1.8 java-17-openjdk, java-21-openjdk, java-21-openjdk-vanilla, java-1.8.0-openjdk-portable Red Hat build of OpenJDK 11 ELS java-11-openjdk, java-17-openjdk, java-21-openjdk, java-21-openjdk-vanilla, java-11-openjdk-portable, java-25-openjdk-portable Red Hat build of OpenJDK 17 java-17-openjdk, java-21-openjdk, java-21-openjdk-vanilla, java-17-openjdk-portable, java-25-openjdk-portable Red Hat build of OpenJDK 21 java-17-openjdk, java-21-openjdk, java-21-openjdk-vanilla, java-21-openjdk-portable, java-25-openjdk-portable Red Hat build of OpenJDK 25 java-25-openjdk-portable Red Hat Enterprise Linux 6 libpng
    +5 more products
    Red Hat Enterprise Linux 7 libpng, firefox, libpng12 Red Hat Enterprise Linux 8 libpng, firefox, libpng12, libpng15, thunderbird, mingw-libpng, +65 more Red Hat Enterprise Linux 9 libpng, firefox, libpng15, firefox-x11, thunderbird, java-17-openjdk, +84 more Red Hat Enterprise Linux 10 libpng, firefox, thunderbird, java-21-openjdk, java-25-openjdk Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images libpng 1.6.57-0.1.hum1, libpng-tools 1.6.57-0.1.hum1
    fixed: vendor fix RHSA-2026:13719

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/pnggroup/libpng/issues/836 referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/pnggroup/libpng/issues/837 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.1 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD 3.1 4.4 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
OSV 3.1 4.4 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
julia libpng_jll
<1.6.57+0
1.6.57+0

Affected products

  • pnggroup libpng

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.