CVE-2026-40930

LIBPNG: Chunk smuggling in push-mode APNG parser via unconsumed chunk body

CVE-2026-40930 is fixed in 6 products on 1 platform, first by DEBIAN-CVE-2026-40930, released May 27, 2026. It is not reported as exploited. Patch Radar priority: Routine.

Routine

CVSS

5.4

Moderate

Exploitation

None reported

No vendor assessment

CISA KEV

Not listed

Not in the Known Exploited Vulnerabilities catalog

EPSS

0.0020

10th percentile

LIBPNG is a reference library for use in applications that process PNG (Portable Network Graphics) raster image files. In version 1.8.0, three inter-frame chunk discard paths in the push-mode APNG parser clear the chunk-header flag without consuming the chunk body and CRC, allowing attacker-controlled bytes inside an ignored ancillary chunk to be reinterpreted as a fresh chunk header on the next call to `png_process_data`. Commit faf06924688b62d7c1654b5ceddedbde66ffadb4 fixes the issue.

Where it's fixed

Product	Fixed in	Fix	Released
Linux
firefox · amzn 2023	140.11.0-1.amzn2023.0.1	ALAS2023-2026-1793	Jun 8, 2026
firefox-debuginfo · amzn 2023	140.11.0-1.amzn2023.0.1	ALAS2023-2026-1793	Jun 8, 2026
firefox-debugsource · amzn 2023	140.11.0-1.amzn2023.0.1	ALAS2023-2026-1793	Jun 8, 2026
libpng-tools · Ubuntu 20.04 LTS (focal)	1.6.37-2ubuntu0.1~esm3	libpng-tools 1.6.37-2ubuntu0.1~esm3	Jun 4, 2026
libpng-tools · Ubuntu 22.04.1 LTS (jammy)	1.6.37-3ubuntu0.6	libpng-tools 1.6.37-3ubuntu0.6	Jun 4, 2026
libpng1.6 · Debian 12.15 (bookworm)	1.6.37-4	DEBIAN-CVE-2026-40930	May 27, 2026
libpng1.6 · Debian 13.5 (trixie)	1.6.37-4	DEBIAN-CVE-2026-40930	May 27, 2026
libpng1.6 · Debian 14	1.6.37-4	DEBIAN-CVE-2026-40930	May 27, 2026
libpng16-16 · Ubuntu 20.04 LTS (focal)	1.6.37-2ubuntu0.1~esm3	libpng16-16 1.6.37-2ubuntu0.1~esm3	Jun 4, 2026
libpng16-16 · Ubuntu 22.04.1 LTS (jammy)	1.6.37-3ubuntu0.6	libpng16-16 1.6.37-3ubuntu0.6	Jun 4, 2026

Details

Published
June 4, 2026
Weakness
Interpretation Conflict
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
Vendor advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40930

For tools and AI agents

This page as data: JSON · Markdown

Link to this page

If this page saved you time, a link to it in your ticket, advisory or write-up helps others find it.

HTML

<a href="https://patchblox.com/security/cve/CVE-2026-40930">CVE-2026-40930 on Patchblox Patch Radar</a>

Reusing the data? How to credit Patch Radar.

Is this on your machines?

Patchblox finds every install below the fixed version on Windows, macOS and Linux, and updates them through your release rings.

Get a demo

Patch Radar data is free to use with attribution. Terms and how to credit it.

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.