CVE-2026-34757
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| debian | bookworm | fixed | 1.6.39-2+deb12u5 |
| debian | bullseye | fixed | 1.6.37-3+deb11u4 |
| debian | forky | fixed | 1.6.57-1 |
| debian | sid | fixed | 1.6.57-1 |
| debian | trixie | fixed | 1.6.48-1+deb13u5 |
| sles | affected | | |
| debian | 11.0 | affected | |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| libpng | libpng | {"startIncluding":"1.0.9","endExcluding":"1.6.57"} | 1.6.57 |
References
- https://github.com/pnggroup/libpng/commit/398cbe3df03f4e11bb031e07f416dfdde3684e8a
- https://github.com/pnggroup/libpng/commit/55d20aaa322c9274491cda82c5cd4f99b48c6bcc
- https://github.com/pnggroup/libpng/issues/836
- https://github.com/pnggroup/libpng/issues/837
- https://github.com/pnggroup/libpng/security/advisories/GHSA-6fr7-g8h7-v645
- https://lists.debian.org/debian-lts-announce/2026/05/msg00017.html
- https://security-tracker.debian.org/tracker/CVE-2026-34757
- https://www.suse.com/security/cve/CVE-2026-34757.html
CWEs
CWE-416
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.