{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-33416","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-03-19T17:02:34.172Z","datePublished":"2026-03-26T16:48:54.174Z","dateUpdated":"2026-04-01T03:55:17.603Z"},"containers":{"cna":{"title":"LIBPNG has use-after-free via pointer aliasing in `png_set_tRNS` and `png_set_PLTE`","problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","description":"CWE-416: Use After Free","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"name":"https://github.com/pnggroup/libpng/security/advisories/GHSA-m4pc-p4q3-4c7j","tags":["x_refsource_CONFIRM"],"url":"https://github.com/pnggroup/libpng/security/advisories/GHSA-m4pc-p4q3-4c7j"},{"name":"https://github.com/pnggroup/libpng/pull/824","tags":["x_refsource_MISC"],"url":"https://github.com/pnggroup/libpng/pull/824"},{"name":"https://github.com/pnggroup/libpng/commit/23019269764e35ed8458e517f1897bd3c54820eb","tags":["x_refsource_MISC"],"url":"https://github.com/pnggroup/libpng/commit/23019269764e35ed8458e517f1897bd3c54820eb"},{"name":"https://github.com/pnggroup/libpng/commit/7ea9eea884a2328cc7fdcb3c0c00246a50d90667","tags":["x_refsource_MISC"],"url":"https://github.com/pnggroup/libpng/commit/7ea9eea884a2328cc7fdcb3c0c00246a50d90667"},{"name":"https://github.com/pnggroup/libpng/commit/a3a21443ed12bfa1ef46fa0d4fb2b74a0fa34a25","tags":["x_refsource_MISC"],"url":"https://github.com/pnggroup/libpng/commit/a3a21443ed12bfa1ef46fa0d4fb2b74a0fa34a25"},{"name":"https://github.com/pnggroup/libpng/commit/c1b0318b393c90679e6fa5bc1d329fd5d5012ec1","tags":["x_refsource_MISC"],"url":"https://github.com/pnggroup/libpng/commit/c1b0318b393c90679e6fa5bc1d329fd5d5012ec1"}],"affected":[{"vendor":"pnggroup","product":"libpng","versions":[{"version":">= 1.2.1, < 1.6.56","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-03-26T16:48:54.174Z"},"descriptions":[{"lang":"en","value":"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."}],"source":{"advisory":"GHSA-m4pc-p4q3-4c7j","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-31T00:00:00+00:00","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3","id":"CVE-2026-33416"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-04-01T03:55:17.603Z"}}]}}