# CVE-2026-40930

## Summary

- **CVE ID:** CVE-2026-40930
- **Severity:** MEDIUM
- **CVSS Score:** 5.4 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L)
- **CWE:** CWE-436
- **Published:** Jun 4, 2026
- **Last Modified:** Sep 14, 2026

## Description

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.

## Affected Products

- pnggroup — libpng (= 1.8.0)
- pnggroup — libpng-apng (>= 1.6.49, <= 1.6.57)

## References

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

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.20%
- **EPSS Percentile:** 10.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._