{"id":"CVE-2026-40492","state":"PUBLISHED","title":"SAIL has heap buffer overflow in XWD decoder — bits_per_pixel vs pixmap_depth type confusion in byte-swap","description":"SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02, the XWD codec resolves pixel format based on `pixmap_depth` but the byte-swap code uses `bits_per_pixel` independently. When `pixmap_depth=8` (BPP8_INDEXED, 1 byte/pixel buffer) but `bits_per_pixel=32`, the byte-swap loop accesses memory as `uint32_t*`, reading/writing 4x the allocated buffer size. This is a different vulnerability from the previously reported GHSA-3g38-x2pj-mv55 (CVE-2026-27168), which addressed `bytes_per_line` validation. Commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02 contains a patch.","publishedAt":"2026-04-18T01:39:48.056Z","updatedAt":"2026-04-20T15:24:42.029Z","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":["HappySeaFox sail"],"affected":[{"vendor":"HappySeaFox","product":"sail","versions":[{"version":"< 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02","status":"affected"}]}],"references":["https://github.com/HappySeaFox/sail/security/advisories/GHSA-526v-vm72-4v64","https://github.com/HappySeaFox/sail/commit/36aa5c7ec8a2bb35f6fb867a1177a6f141156b02"],"weaknesses":["CWE-787"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/40xxx/CVE-2026-40492.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40492","state":"PUBLISHED","datePublished":"2026-04-18T01:39:48.056Z","dateUpdated":"2026-04-20T15:24:42.029Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-04-13T19:50:42.115Z"},"containers":{"cna":{"title":"SAIL has heap buffer overflow in XWD decoder — bits_per_pixel vs pixmap_depth type confusion in byte-swap","descriptions":[{"lang":"en","value":"SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02, the XWD codec resolves pixel format based on `pixmap_depth` but the byte-swap code uses `bits_per_pixel` independently. When `pixmap_depth=8` (BPP8_INDEXED, 1 byte/pixel buffer) but `bits_per_pixel=32`, the byte-swap loop accesses memory as `uint32_t*`, reading/writing 4x the allocated buffer size. This is a different vulnerability from the previously reported GHSA-3g38-x2pj-mv55 (CVE-2026-27168), which addressed `bytes_per_line` validation. Commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02 contains a patch."}],"affected":[{"vendor":"HappySeaFox","product":"sail","versions":[{"version":"< 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02","status":"affected"}]}],"references":[{"url":"https://github.com/HappySeaFox/sail/security/advisories/GHSA-526v-vm72-4v64","name":"https://github.com/HappySeaFox/sail/security/advisories/GHSA-526v-vm72-4v64","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/HappySeaFox/sail/commit/36aa5c7ec8a2bb35f6fb867a1177a6f141156b02","name":"https://github.com/HappySeaFox/sail/commit/36aa5c7ec8a2bb35f6fb867a1177a6f141156b02","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":"2026-04-18T01:39:48.056Z"},"source":{"advisory":"GHSA-526v-vm72-4v64","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/HappySeaFox/sail/security/advisories/GHSA-526v-vm72-4v64","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-20T15:24:38.837811Z","id":"CVE-2026-40492","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":"2026-04-20T15:24:42.029Z"}}]}}}