CVE-2026-40930: pnggroup libpng · Interpretation Conflict
Affects pnggroup libpngSource CVE Database V5
Not known to be exploited · CVSS 5.4 Medium.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:LExploitation evidence
Disclosed: evidence found.
CVE published 4 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| pnggrouplibpng | Affected
| Fixed in– |
| pnggrouplibpng-apng | Affected
| Fixed in– |
GitHubpnggroup/libpngpkg:github/pnggroup/libpngOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Users of libpng version 1.8.0 should monitor vendor channels for an official fix and consider avoiding use of this version until remediation is confirmed.
Description
A vulnerability in libpng version 1.8.0 involves an interpretation conflict in the APNG parser's handling of ancillary chunks. Specifically, certain discard paths clear the chunk-header flag without consuming the chunk body and CRC, which may allow attacker-controlled data to be misinterpreted as new chunk headers. This issue is identified as CWE-436 and has a CVSS score of 5.4, indicating medium severity.