CVE-2026-40930LIBPNG: Chunk smuggling in push-mode APNG parser via unconsumed chunk body
Updated under an hour ago ()
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It affects pnggroup libpng and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Free account, 1 product
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.
- CVSS
- 5.4 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
- Weakness (CWE)
- CWE-436
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Awaiting Analysis
- Record last updated
- Jun 4, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
pnggroup libpng pnggroup:libpng (from the name) | = 1.8.0 | CNA record |
pnggroup libpng-apng pnggroup:libpng_apng (from the name) | from 1.6.49, <= 1.6.57 | CNA record |
References
- https://github.com/pnggroup/libpng/security/advisories/GHSA-c4v6-gxrq-6g2xx-refsource-confirm
- https://github.com/pnggroup/libpng/commit/faf06924688b62d7c1654b5ceddedbde66ffadb4x-refsource-misc
- http://www.openwall.com/lists/oss-security/2026/05/15/21
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.