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Fencer Vulns
high 7.6

CVE-2026-33636 json

LIBPNG has ARM NEON Palette Expansion Out-of-Bounds Read on AArch64

published 2026-03-26 7 mo ago modified 2026-07-18 3 mo ago also EUVD-2026-16269 , JLSEC-2026-96

cvss
7.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 55%
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. In versions 1.6.36 through 1.6.55, an out-of-bounds read and write exists in libpng's ARM/AArch64 Neon-optimized palette expansion path. When expanding 8-bit paletted rows to RGB or RGBA, the Neon loop processes a final partial chunk without verifying that enough input pixels remain. Because the implementation works backward from the end of the row, the final iteration dereferences pointers before the start of the row buffer (OOB read) and writes expanded pixel data to the same underflowed positions (OOB write). This is reachable via normal decoding of attacker-controlled PNG input if Neon is enabled. Version 1.6.56 fixes the issue.

Patch / fix

  • julia libpng_jll 1.6.56+0
  • libpng libpng 1.6.56
  • libpng1.6 Debian 12 1.6.39-2+deb12u4
  • libpng1.6 Debian 13 1.6.48-1+deb13u4
  • libpng1.6 Debian 14 1.6.56-1

debian advisories DEBIAN-CVE-2026-33636

  • 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
  • libpng1.6 Ubuntu Pro 20.04 LTS 1.6.37-2ubuntu0.1~esm3

ubuntu advisories UBUNTU-CVE-2026-33636

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 1.6.58-2.1.hum1
  • libpng-tools hummingbird 1 1.6.58-2.1.hum1
  • libpng RHEL 9 2:1.6.37-15.el9_8.2
  • libpng RHEL 10.2 2:1.6.40-11.el10_2.1
  • libpng RHEL 9 2:1.6.37-12.el9_7.3
  • libpng RHEL 10.1 2:1.6.40-8.el10_1.3
  • java-21-openjdk RHEL 10.1 1:21.0.11.0.10-2.el10_2
  • java-21-openjdk RHEL 8 1:21.0.11.0.10-1.el8

red hat advisories RHSA-2026:80330RHSA-2026:28255RHSA-2026:28233RHSA-2026:17685RHSA-2026:17642RHSA-2026:17603

  • libpng16 Linux Micro 6.1 1.6.58-slfo.1.1_1.1
  • libpng16 Linux Micro 6.0 1.6.58-1.1
  • libpng16 SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Basesystem 15 SP7 +1 more 1.6.40-150600.3.17.1
  • libpng16 Linux Micro 6.1 1.6.43-slfo.1.1_4.1
  • libpng16 Linux Micro 6.0 1.6.43-4.1
  • libpng16 SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 1.6.44-160000.6.1

suse advisories SUSE-SU-2026:23514-1SUSE-SU-2026:23063-1SUSE-SU-2026:1368-1SUSE-SU-2026:21038-1SUSE-SU-2026:21067-1SUSE-SU-2026:21000-1

  • libpng16 openSUSE Leap 16.0 1.6.44-160000.6.1
  • libpng16 openSUSE Tumbleweed 1.6.56-1.1

opensuse advisories openSUSE-SU-2026:20466-1openSUSE-SU-2026:10451-1

  • libpng AlmaLinux 10 2:1.6.40-11.el10_2.1
  • libpng AlmaLinux 9 2:1.6.37-15.el9_8.2
  • libpng AlmaLinux 10 2:1.6.40-8.el10_1.3
  • libpng AlmaLinux 9 2:1.6.37-12.el9_7.3
  • java-1.8.0-openjdk AlmaLinux 8 1:1.8.0.492.b09-1.el8
  • java-1.8.0-openjdk AlmaLinux 9 1:1.8.0.492.b09-2.el9.alma.1
  • java-1.8.0-openjdk-src AlmaLinux 8 1:1.8.0.492.b09-1.el8
  • java-1.8.0-openjdk-src AlmaLinux 9 1:1.8.0.492.b09-2.el9.alma.1

almalinux advisories ALSA-2026:28233ALSA-2026:28255ALSA-2026:14790ALSA-2026:14791ALSA-2026:9683ALSA-2026:9686

  • libpng Rocky Linux 10 2:1.6.40-11.el10_2.1
  • libpng Rocky Linux 9 2:1.6.37-15.el9_8.2
  • java-25-openjdk Rocky Linux 10 1:25.0.3.0.9-1.el10_1
  • libpng Rocky Linux 10 2:1.6.40-8.el10_1.3
  • libpng Rocky Linux 9 2:1.6.37-12.el9_7.3
  • thunderbird Rocky Linux 10 140.9.1-1.el10_1
  • thunderbird Rocky Linux 8 140.9.1-1.el8_10
  • thunderbird Rocky Linux 9 140.9.1-1.el9_7

rocky linux advisories RLSA-2026:28233RLSA-2026:28255RLSA-2026:9693RLSA-2026:14790RLSA-2026:14791RLSA-2026:9638

  • libpng Alpine 3.24, Alpine 3.23, Alpine 3.22 +2 more 1.6.56-r0

alpine advisories ALPINE-CVE-2026-33636

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 1.6.56-1

azure linux advisories AZL-80993

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-2026-33636 updated cvss 7.6

libpng: libpng: Information disclosure and denial of service via out-of-bounds read/write in Neon palette expansion

  • Red Hat build of OpenJDK 1.8 java-17-openjdk, java-21-openjdk, java-21-openjdk-vanilla Red Hat build of OpenJDK 11 ELS java-17-openjdk, java-21-openjdk, java-21-openjdk-vanilla, java-25-openjdk-portable Red Hat build of OpenJDK 17 java-17-openjdk, java-21-openjdk, java-21-openjdk-vanilla, java-25-openjdk-portable Red Hat build of OpenJDK 21 java-17-openjdk, java-21-openjdk, java-21-openjdk-vanilla, java-25-openjdk-portable
    affected: workaround, no fix available
  • Red Hat Enterprise Linux 6 libpng
    affected: workaround, no fix planned “Will not fix”
  • Red Hat OPENJDK ELS 11.0.31
    fixed: vendor fix RHSA-2026:9255
  • Red Hat AI Inference Server 3.2 rhaiis/model-opt-cuda-rhel9 1780681984
    fixed: vendor fix RHSA-2026:25096
  • Red Hat Build of OpenJDK 8u492
    fixed: vendor fix RHSA-2026:9684
  • Red Hat Build of OpenJDK 17.0.9
    fixed: vendor fix RHSA-2026:9687
  • Red Hat Build of OpenJDK 21.0.11
    fixed: vendor fix RHSA-2026:9690
  • Red Hat Build of OpenJDK 25.0.3
    fixed: vendor fix RHSA-2026:9694
show 15 more
  • Red Hat CodeReady Linux Builder EUS (v.9.4) java-17-openjdk-fastdebug 17.0.19.0.10-1.el9, java-17-openjdk-slowdebug 17.0.19.0.10-1.el9, java-21-openjdk-fastdebug 21.0.11.0.10-1.el9, java-21-openjdk-slowdebug 21.0.11.0.10-1.el9, java-1.8.0-openjdk-fastdebug 1.8.0.492.b09-1.el9, java-1.8.0-openjdk-slowdebug 1.8.0.492.b09-1.el9, +32 more Red Hat CodeReady Linux Builder EUS (v.9.6) java-17-openjdk-fastdebug 17.0.19.0.10-1.el9, java-17-openjdk-slowdebug 17.0.19.0.10-1.el9, java-21-openjdk-fastdebug 21.0.11.0.10-1.el9, java-21-openjdk-slowdebug 21.0.11.0.10-1.el9, java-1.8.0-openjdk-fastdebug 1.8.0.492.b09-1.el9, java-1.8.0-openjdk-slowdebug 1.8.0.492.b09-1.el9, +32 more
    fixed: vendor fix RHSA-2026:9689
  • Red Hat Discovery 2 discovery/discovery-ui-rhel9 1782756541
    fixed: vendor fix RHSA-2026:33313
  • Red Hat Enterprise Linux AppStream (v. 8) firefox 140.9.1-1.el8_10, thunderbird 140.9.1-1.el8_10, java-17-openjdk 17.0.19.0.10-1.el8, java-21-openjdk 21.0.11.0.10-1.el8, java-1.8.0-openjdk 1.8.0.492.b09-1.el8, java-17-openjdk-src 17.0.19.0.10-1.el8, +19 more Red Hat Enterprise Linux AppStream (v. 9) firefox 140.9.1-1.el9_7, libpng 1.6.37-12.el9_7.3, libpng 1.6.37-15.el9_8.2, firefox-x11 140.9.1-1.el9_7, thunderbird 140.9.1-1.el9_7, java-25-openjdk 25.0.3.0.9-1.el9, +30 more Red Hat Enterprise Linux AppStream (v. 10) firefox 140.9.1-1.el10_1, libpng 1.6.40-8.el10_1.3, libpng 1.6.40-11.el10_2.1, thunderbird 140.9.1-1.el10_1, java-25-openjdk 25.0.3.0.9-1.el10_2, java-21-openjdk 21.0.11.0.10-2.el10_2, +15 more
    fixed: vendor fix RHSA-2026:9689
  • Red Hat Enterprise Linux AppStream AUS (v. 8.2) firefox 140.9.1-1.el8_2, java-1.8.0-openjdk 1.8.0.492.b09-1.el8, java-1.8.0-openjdk-src 1.8.0.492.b09-1.el8, java-1.8.0-openjdk-demo 1.8.0.492.b09-1.el8, java-1.8.0-openjdk-javadoc 1.8.0.492.b09-1.el8, java-1.8.0-openjdk-headless 1.8.0.492.b09-1.el8, +2 more Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox 140.9.1-1.el8_4, thunderbird 140.9.1-1.el8_4, java-17-openjdk 17.0.19.0.10-1.el8, java-1.8.0-openjdk 1.8.0.492.b09-1.el8, java-17-openjdk-src 17.0.19.0.10-1.el8, java-17-openjdk-demo 17.0.19.0.10-1.el8, +11 more Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox 140.9.1-1.el8_6, thunderbird 140.9.1-1.el8_6, java-17-openjdk 17.0.19.0.10-1.el8, java-1.8.0-openjdk 1.8.0.492.b09-1.el8, java-17-openjdk-src 17.0.19.0.10-1.el8, java-17-openjdk-demo 17.0.19.0.10-1.el8, +11 more Red Hat Enterprise Linux AppStream E4S (v.8.6) firefox 140.9.1-1.el8_6, thunderbird 140.9.1-1.el8_6, java-17-openjdk 17.0.19.0.10-1.el8, java-1.8.0-openjdk 1.8.0.492.b09-1.el8, java-17-openjdk-src 17.0.19.0.10-1.el8, java-17-openjdk-demo 17.0.19.0.10-1.el8, +11 more Red Hat Enterprise Linux AppStream E4S (v.8.8) firefox 140.9.1-1.el8_8, thunderbird 140.9.1-1.el8_8, java-17-openjdk 17.0.19.0.10-1.el8, java-1.8.0-openjdk 1.8.0.492.b09-1.el8, java-17-openjdk-src 17.0.19.0.10-1.el8, java-17-openjdk-demo 17.0.19.0.10-1.el8, +11 more Red Hat Enterprise Linux AppStream E4S (v.9.0) firefox 140.9.1-1.el9_0, libpng 1.6.37-12.el9_0.3, thunderbird 140.9.1-1.el9_0, java-17-openjdk 17.0.19.0.10-1.el9, java-1.8.0-openjdk 1.8.0.492.b09-1.el9, java-17-openjdk-src 17.0.19.0.10-1.el9, +11 more
    +1 more products
    Red Hat Enterprise Linux AppStream E4S (v.9.2) firefox 140.9.1-1.el9_2, libpng 1.6.37-12.el9_2.3, firefox-x11 140.9.1-1.el9_2, thunderbird 140.9.1-1.el9_2, java-17-openjdk 17.0.19.0.10-1.el9, java-1.8.0-openjdk 1.8.0.492.b09-1.el9, +12 more
    fixed: vendor fix RHSA-2026:9683
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) firefox 140.9.1-1.el10_0, libpng 1.6.40-8.el10_0.3, thunderbird 140.9.1-1.el10_0, java-21-openjdk 21.0.11.0.10-1.el10_2, java-21-openjdk-src 21.0.11.0.10-1.el10_2, java-21-openjdk-demo 21.0.11.0.10-1.el10_2, +5 more
    fixed: vendor fix RHSA-2026:13665
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) firefox 140.9.1-1.el9_4, libpng 1.6.37-12.el9_4.3, firefox-x11 140.9.1-1.el9_4, thunderbird 140.9.1-1.el9_4, java-17-openjdk 17.0.19.0.10-1.el9, java-21-openjdk 21.0.11.0.10-1.el9, +20 more Red Hat Enterprise Linux AppStream EUS (v.9.6) firefox 140.9.1-1.el9_6, libpng 1.6.37-12.el9_6.3, firefox-x11 140.9.1-1.el9_6, thunderbird 140.9.1-1.el9_6, java-17-openjdk 17.0.19.0.10-1.el9, java-21-openjdk 21.0.11.0.10-1.el9, +20 more
    fixed: vendor fix RHSA-2026:9689
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) firefox 140.9.1-1.el8_4, thunderbird 140.9.1-1.el8_4, java-17-openjdk 17.0.19.0.10-1.el8, java-1.8.0-openjdk 1.8.0.492.b09-1.el8, java-17-openjdk-src 17.0.19.0.10-1.el8, java-17-openjdk-demo 17.0.19.0.10-1.el8, +25 more Red Hat Enterprise Linux AppStream TUS (v.8.6) firefox 140.9.1-1.el8_6, thunderbird 140.9.1-1.el8_6, java-17-openjdk 17.0.19.0.10-1.el8, java-1.8.0-openjdk 1.8.0.492.b09-1.el8, java-17-openjdk-src 17.0.19.0.10-1.el8, java-17-openjdk-demo 17.0.19.0.10-1.el8, +11 more Red Hat Enterprise Linux AppStream TUS (v.8.8) firefox 140.9.1-1.el8_8, thunderbird 140.9.1-1.el8_8, java-17-openjdk 17.0.19.0.10-1.el8, java-1.8.0-openjdk 1.8.0.492.b09-1.el8, java-17-openjdk-src 17.0.19.0.10-1.el8, java-17-openjdk-demo 17.0.19.0.10-1.el8, +11 more
    fixed: vendor fix RHSA-2026:9683
  • Red Hat Enterprise Linux BaseOS (v. 9) libpng 1.6.37-12.el9_7.3, libpng 1.6.37-15.el9_8.2
    fixed: vendor fix RHSA-2026:14791
  • Red Hat Enterprise Linux BaseOS (v. 10) libpng 1.6.40-8.el10_1.3, libpng 1.6.40-11.el10_2.1
    fixed: vendor fix RHSA-2026:14790
  • Red Hat Enterprise Linux BaseOS E4S (v.9.0) libpng 1.6.37-12.el9_0.3
    fixed: vendor fix RHSA-2026:17685
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) libpng 1.6.37-12.el9_2.3
    fixed: vendor fix RHSA-2026:17642
  • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) libpng 1.6.40-8.el10_0.3
    fixed: vendor fix RHSA-2026:17567
  • Red Hat Enterprise Linux BaseOS EUS (v.9.4) libpng 1.6.37-12.el9_4.3
    fixed: vendor fix RHSA-2026:17603
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) libpng 1.6.37-12.el9_6.3
    fixed: vendor fix RHSA-2026:17524
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) java-25-openjdk-fastdebug 25.0.3.0.9-1.el9, java-25-openjdk-slowdebug 25.0.3.0.9-1.el9, java-17-openjdk-fastdebug 17.0.19.0.10-2.el9, java-17-openjdk-slowdebug 17.0.19.0.10-2.el9, java-21-openjdk-fastdebug 21.0.11.0.10-2.el9, java-21-openjdk-slowdebug 21.0.11.0.10-2.el9, +48 more Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) java-25-openjdk-fastdebug 25.0.3.0.9-1.el10_2, java-25-openjdk-slowdebug 25.0.3.0.9-1.el10_2, java-21-openjdk-fastdebug 21.0.11.0.10-2.el10_2, java-21-openjdk-slowdebug 21.0.11.0.10-2.el10_2, java-25-openjdk-src-fastdebug 25.0.3.0.9-1.el10_2, java-25-openjdk-src-slowdebug 25.0.3.0.9-1.el10_2, +24 more Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) java-21-openjdk-fastdebug 21.0.11.0.10-1.el10_2, java-21-openjdk-slowdebug 21.0.11.0.10-1.el10_2, java-21-openjdk-src-fastdebug 21.0.11.0.10-1.el10_2, java-21-openjdk-src-slowdebug 21.0.11.0.10-1.el10_2, java-21-openjdk-demo-fastdebug 21.0.11.0.10-1.el10_2, java-21-openjdk-demo-slowdebug 21.0.11.0.10-1.el10_2, +8 more
    fixed: vendor fix RHSA-2026:9689

7 more fixed, 15 more not affected in the full advisory

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
none
Automatable
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.75% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
OSV 3.1 7.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H

Affected packages

ecosystem package affected fixed in
julia libpng_jll
<1.6.56+0
1.6.56+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.