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Home/Vulnerability/CVE-2026-40930

CVE-2026-40930

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

Published: Jun 4, 2026Updated: Jun 4, 2026 Sources: CVE List NVD
NVD MITRE
5.4CVSS
MEDIUM

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.

EPSS Score
0.0%
Top 89.5%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

CVSS Vector Breakdown

AV:NAC:LPR:NUI:RS:UC:NI:LA:L
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:LIntegrity
Low
A:LAvailability
Low

Weaknesses

CWE-436

Affected Products

libpng
pnggroup
OSS Libraries / generic-library
libpng-apng
pnggroup
OSS Libraries / generic-library
pnggrouposs-projectOSS Librariesaka libpng

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

References

https://github.com/pnggroup/libpng/security/advisories/GHSA-c4v6-gxrq-6g2x
github.com
https://github.com/pnggroup/libpng/commit/faf06924688b62d7c1654b5ceddedbde66ffadb4
github.com
http://www.openwall.com/lists/oss-security/2026/05/15/21
openwall.com

Timeline

Published
Jun 4, 2026
Last Updated
Jun 4, 2026
News mentions
1

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