CVE-2026-25646
Modified
Modified - Updated After Analysis
Out-of-Bounds Read in LIBPNG png_set_quantize() Causes Infinite Loop
Vulnerability report for CVE-2026-25646, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-02-10
Last updated on: 2026-06-30
Assigner: GitHub, Inc.
Description
Description
LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Prior to 1.6.55, an out-of-bounds read vulnerability exists in the png_set_quantize() API function. When the function is called with no histogram and the number of colors in the palette is more than twice the maximum supported by the user's display, certain palettes will cause the function to enter into an infinite loop that reads past the end of an internal heap-allocated buffer. The images that trigger this vulnerability are valid per the PNG specification. This vulnerability is fixed in 1.6.55.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| libpng | libpng | to 1.6.55 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-126 | The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer. |
| CWE-122 | A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). |
| CWE-125 | The product reads data past the end, or before the beginning, of the intended buffer. |
