{"id":"CVE-2026-33416","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-33416","generatedAt":"2026-10-28T10:39:58.083Z","title":"LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files.","description":"LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. In versions 1.2.1 through 1.6.55, `png_set_tRNS` and `png_set_PLTE` each alias a heap-allocated buffer between `png_struct` and `png_info`, sharing a single allocation across two structs with independent lifetimes. The `trans_alpha` aliasing has been present since at least libpng 1.0, and the `palette` aliasing since at least 1.2.1. Both affect all prior release lines `png_set_tRNS` sets `png_ptr->trans_alpha = info_ptr->trans_alpha` (256-byte buffer) and `png_set_PLTE` sets `info_ptr->palette = png_ptr->palette` (768-byte buffer). In both cases, calling `png_free_data` (with `PNG_FREE_TRNS` or `PNG_FREE_PLTE`) frees the buffer through `info_ptr` while the corresponding `png_ptr` pointer remains dangling. Subsequent row-transform functions dereference and, in some code paths, write to the freed memory. A second call to `png_set_tRNS` or `png_set_PLTE` has the same effect, because both functions call `png_free_data` internally before reallocating the `info_ptr` buffer. Version 1.6.56 fixes the issue.","published":"2026-03-26T17:16:38.000Z","lastModified":"2026-06-17T10:37:28.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H"},"cwe":["CWE-416"],"affected":["libpng/libpng"],"epss":{"score":0.01071,"percentile":0.64689,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (1.07%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/pnggroup/libpng/commit/23019269764e35ed8458e517f1897bd3c54820eb","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/pnggroup/libpng/commit/7ea9eea884a2328cc7fdcb3c0c00246a50d90667","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/pnggroup/libpng/commit/a3a21443ed12bfa1ef46fa0d4fb2b74a0fa34a25","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/pnggroup/libpng/commit/c1b0318b393c90679e6fa5bc1d329fd5d5012ec1","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/pnggroup/libpng/pull/824","tags":["Exploit","Issue Tracking"],"source":"security-advisories@github.com"},{"url":"https://github.com/pnggroup/libpng/security/advisories/GHSA-m4pc-p4q3-4c7j","tags":["Patch","Vendor Advisory"],"source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-33416","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}