{"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": "2026-03-26T16:48:54.174Z"}, "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"}}}}

{}

{"cveTags": [], "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."}], "id": "CVE-2026-33416", "lastModified": "2026-03-26T17:16:38.443", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 1.6, "impactScore": 5.9, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-03-26T17:16:38.443", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/pnggroup/libpng/commit/23019269764e35ed8458e517f1897bd3c54820eb"}, {"source": "security-advisories@github.com", "url": "https://github.com/pnggroup/libpng/commit/7ea9eea884a2328cc7fdcb3c0c00246a50d90667"}, {"source": "security-advisories@github.com", "url": "https://github.com/pnggroup/libpng/commit/a3a21443ed12bfa1ef46fa0d4fb2b74a0fa34a25"}, {"source": "security-advisories@github.com", "url": "https://github.com/pnggroup/libpng/commit/c1b0318b393c90679e6fa5bc1d329fd5d5012ec1"}, {"source": "security-advisories@github.com", "url": "https://github.com/pnggroup/libpng/pull/824"}, {"source": "security-advisories@github.com", "url": "https://github.com/pnggroup/libpng/security/advisories/GHSA-m4pc-p4q3-4c7j"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}