{"id":"CVE-2026-44638","state":"PUBLISHED","title":"libsixel: NULL pointer dereference","description":"libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From  to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer dereference whenever the allocation fails. The check tests the address of the output parameter (always non-NULL) instead of the value the malloc returned. On allocation failure, the function continues and writes through a NULL pointer, crashing the process. This is a denial of service against any caller of these public APIs that hits a low-memory condition. This vulnerability is fixed in 1.8.7-r2.","publishedAt":"2026-05-14T19:59:29.704Z","updatedAt":"2026-05-15T14:18:03.581Z","severity":{"score":2.5,"label":"Low","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["saitoha libsixel"],"affected":[{"vendor":"saitoha","product":"libsixel","versions":[{"version":">= 1.0.0, < 1.8.7-r2","status":"affected"}]}],"references":["https://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3w"],"weaknesses":["CWE-476","CWE-690"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/44xxx/CVE-2026-44638.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-44638","state":"PUBLISHED","datePublished":"2026-05-14T19:59:29.704Z","dateUpdated":"2026-05-15T14:18:03.581Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-07T15:30:10.875Z"},"containers":{"cna":{"title":"libsixel: NULL pointer dereference","descriptions":[{"lang":"en","value":"libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From  to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer dereference whenever the allocation fails. The check tests the address of the output parameter (always non-NULL) instead of the value the malloc returned. On allocation failure, the function continues and writes through a NULL pointer, crashing the process. This is a denial of service against any caller of these public APIs that hits a low-memory condition. This vulnerability is fixed in 1.8.7-r2."}],"affected":[{"vendor":"saitoha","product":"libsixel","versions":[{"version":">= 1.0.0, < 1.8.7-r2","status":"affected"}]}],"references":[{"url":"https://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3w","name":"https://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3w","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"LOW","baseScore":2.5,"baseSeverity":"LOW","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-476","lang":"en","description":"CWE-476: NULL Pointer Dereference","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-690","lang":"en","description":"CWE-690: Unchecked Return Value to NULL Pointer Dereference","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-05-14T19:59:29.704Z"},"source":{"advisory":"GHSA-wpx3-h5g8-qr3w","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3w","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-15T14:17:38.241135Z","id":"CVE-2026-44638","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-15T14:18:03.581Z"}}]}}}