CVE-2026-34757
LIBPNG has a yse-after-free in png_set_PLTE, png_set_tRNS and png_set_hIST leading to corrupted chunk data and potential heap information disclosure
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium5.1 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
| NVDNVD · Analyzed | 3.1 | Medium4.4 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.20% · top 90% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.1.
Weakness
Affected products
References (6)
- https://github.com/pnggroup/libpng/security/advisories/GHSA-6fr7-g8h7-v645 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/pnggroup/libpng/issues/836 (opens in a new tab)x_refsource_MISC
- https://github.com/pnggroup/libpng/issues/837 (opens in a new tab)x_refsource_MISC
- https://github.com/pnggroup/libpng/commit/398cbe3df03f4e11bb031e07f416dfdde3684e8a (opens in a new tab)x_refsource_MISC
- https://github.com/pnggroup/libpng/commit/55d20aaa322c9274491cda82c5cd4f99b48c6bcc (opens in a new tab)x_refsource_MISC
- https://lists.debian.org/debian-lts-announce/2026/05/msg00017.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-34757)Record last updated .