CVE-2025-64506 LIBPNG is vulnerable to a heap buffer over-read in `png_write_image_8bit` with grayscale+alpha or RGB/RGBA images
A heap buffer over-read in libpng allows attackers to cause denial of service or disclose memory contents when processing specific 8-bit images.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2025-64506?
CVE-2025-64506 is a medium-severity memory corruption vulnerability in Libpng Libpng, published on 24 Nov 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From version 1.6.0 to before 1.6.51, a heap buffer over-read vulnerability exists in libpng's png_write_image_8bit function when processing 8-bit images through the simplified write API with convert_to_8bit enabled. The vulnerability affects 8-bit grayscale+alpha, RGB/RGBA, and images with incomplete row data. A conditional guard incorrectly allows 8-bit input to enter code expecting 16-bit input, causing reads up to 2 bytes beyond allocated buffer boundaries. This issue has been patched in version 1.6.51.
Weakness: CWE-125
Which versions are affected by CVE-2025-64506?
It affects 1 product.
Products include Libpng Libpng.
How do I fix CVE-2025-64506?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-64506 being exploited?
There is no known exploitation of CVE-2025-64506 in the wild and no public exploit code.
Other vulnerabilities in Libpng Libpng
- CVE-2017-12652 Denial of service in n/a
- CVE-2018-14550 Out-of-bounds write in libpng
- CVE-2026-25646 LIBPNG has a heap buffer overflow in png_set_quantize
- CVE-2026-33636 LIBPNG has ARM NEON Palette Expansion Out-of-Bounds Read on AArch64
- CVE-2026-33416 LIBPNG has use-after-free via pointer aliasing in `png_set_tRNS` and `png_set_PLTE`
Sources
Also known as ALPINE-CVE-2025-64506, AZL-70841, AZL-70856, AZL-70871, AZL-70886, AZL-70897 and 12 more.