Description
LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From 1.0.9 to before 1.6.57, passing a pointer obtained from png_get_PLTE, png_get_tRNS, or png_get_hIST back into the corresponding setter on the same png_struct/png_info pair causes the setter to read from freed memory and copy its contents into the replacement buffer. The setter frees the internal buffer before copying from the caller-supplied pointer, which now dangles. The freed region may contain stale data (producing silently corrupted chunk metadata) or data from subsequent heap allocations (leaking unrelated heap contents into the chunk struct). This vulnerability is fixed in 1.6.57.
Affected products
libpng: libpng; debian: debian linux
References6
- github.com/pnggroup/libpng/security/advisories/GHSA-6fr7-g8h7-v… MitigationPatchVendor Advisory
- github.com/pnggroup/libpng/commit/398cbe3df03f4e11bb031e07f416d… Patch
- github.com/pnggroup/libpng/commit/55d20aaa322c9274491cda82c5cd4… Patch
- github.com/pnggroup/libpng/issues/836 ExploitIssue TrackingMitigation
- github.com/pnggroup/libpng/issues/837 ExploitIssue TrackingMitigation
- lists.debian.org/debian-lts-announce/2026/05/msg00017.html Mailing ListThird Party Advisory
Metrics
- CVSS 3.1
-
4.4
MEDIUM
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 10 · as of 12 November 2026
- CWE
- CWE-416
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