{"id":"CVE-2026-84383","state":"PUBLISHED","title":"libheif: Heap buffer overflow in `scale_nearest_neighbor()` via duplicate Alpha planes from nested `iden`/`auxl` items","description":"libheif is a HEIF and AVIF file format decoder and encoder. From 1.22.0 until 1.23.2, a crafted HEIF, HEIC, or AVIF item graph using nested iden and auxl references can make HeifPixelImage::transfer_channel_from_image_as() append duplicate Alpha planes with different bit depths to m_storage. HeifPixelImage::scale_nearest_neighbor() in libheif/image/pixelimage.cc allocates the destination Alpha plane using the first plane's 8-bit depth, then iterates a later 10-bit or 12-bit Alpha component and writes uint16_t samples into the same 8-bit allocation. The output geometry controls the overflow extent and the encoded sample values control the data written, allowing a remote file processed by heif_decode_image() to cause a heap out-of-bounds write. This issue is fixed in version 1.23.2.","publishedAt":"2026-09-18T15:55:46.914Z","updatedAt":"2026-09-18T16:11:18.781Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["strukturag libheif"],"affected":[{"vendor":"strukturag","product":"libheif","versions":[{"version":">= 1.22.0, < 1.23.2","status":"affected"}]}],"references":["https://github.com/strukturag/libheif/security/advisories/GHSA-g89c-p67h-r497","https://github.com/strukturag/libheif/commit/f4fb8bde4704ebb46e46ff9fb94407c9774153b2","https://github.com/strukturag/libheif/releases/tag/v1.23.2"],"weaknesses":["CWE-787"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/84xxx/CVE-2026-84383.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-84383","state":"PUBLISHED","datePublished":"2026-09-18T15:55:46.914Z","dateUpdated":"2026-09-18T16:11:18.781Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-01T16:27:58.130Z"},"containers":{"cna":{"title":"libheif: Heap buffer overflow in `scale_nearest_neighbor()` via duplicate Alpha planes from nested `iden`/`auxl` items","descriptions":[{"lang":"en","value":"libheif is a HEIF and AVIF file format decoder and encoder. From 1.22.0 until 1.23.2, a crafted HEIF, HEIC, or AVIF item graph using nested iden and auxl references can make HeifPixelImage::transfer_channel_from_image_as() append duplicate Alpha planes with different bit depths to m_storage. HeifPixelImage::scale_nearest_neighbor() in libheif/image/pixelimage.cc allocates the destination Alpha plane using the first plane's 8-bit depth, then iterates a later 10-bit or 12-bit Alpha component and writes uint16_t samples into the same 8-bit allocation. The output geometry controls the overflow extent and the encoded sample values control the data written, allowing a remote file processed by heif_decode_image() to cause a heap out-of-bounds write. This issue is fixed in version 1.23.2."}],"affected":[{"vendor":"strukturag","product":"libheif","versions":[{"version":">= 1.22.0, < 1.23.2","status":"affected"}]}],"references":[{"url":"https://github.com/strukturag/libheif/security/advisories/GHSA-g89c-p67h-r497","name":"https://github.com/strukturag/libheif/security/advisories/GHSA-g89c-p67h-r497","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/strukturag/libheif/commit/f4fb8bde4704ebb46e46ff9fb94407c9774153b2","name":"https://github.com/strukturag/libheif/commit/f4fb8bde4704ebb46e46ff9fb94407c9774153b2","tags":["x_refsource_MISC"]},{"url":"https://github.com/strukturag/libheif/releases/tag/v1.23.2","name":"https://github.com/strukturag/libheif/releases/tag/v1.23.2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":9.8,"baseSeverity":"CRITICAL","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-787","lang":"en","description":"CWE-787: Out-of-bounds Write","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-18T15:55:46.914Z"},"source":{"advisory":"GHSA-g89c-p67h-r497","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/strukturag/libheif/security/advisories/GHSA-g89c-p67h-r497","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-18T16:07:46.621200Z","id":"CVE-2026-84383","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-18T16:11:18.781Z"}}]}}}