LIBPNG is vulnerable to a heap buffer overflow in `png_do_quantize` via malformed palette index

Open Source Vulnerabilities ASB-A-463980379

In png_init_read_transformations of pngrtran.c, there is a possible way to cause a persistent denial of service due to a heap buffer overflow. This could lead to local denial of service with no additional execution privileges needed. User interaction is not needed for exploitation.

Open Source Vulnerabilities CVE-2025-64505

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Prior to version 1.6.51, a heap buffer over-read vulnerability exists in libpng's png_do_quantize function when processing PNG files with malformed palette indices. The vulnerability occurs when palette_lookup array bounds are not validated against externally-supplied image data, allowing an attacker to craft a PNG file with out-of-range palette indices that trigger out-of-bounds memory access. This issue has been patched in version 1.6.51.