{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-04-21T05:02:57.265","vulnerabilities":[{"cve":{"id":"CVE-2026-33021","sourceIdentifier":"security-advisories@github.com","published":"2026-04-14T23:16:27.660","lastModified":"2026-04-17T15:38:09.243","vulnStatus":"Undergoing Analysis","cveTags":[],"descriptions":[{"lang":"en","value":"libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain a use-after-free vulnerability in sixel_encoder_encode_bytes() because sixel_frame_init() stores the caller-owned pixel buffer pointer directly in frame->pixels without making a defensive copy. When a resize operation is triggered, sixel_frame_convert_to_rgb888() unconditionally frees this caller-owned buffer and replaces it with a new internal allocation, leaving the caller with a dangling pointer. Any subsequent access to the original buffer by the caller constitutes a use-after-free, confirmed by AddressSanitizer. An attacker who controls incoming frames can trigger this bug repeatedly and predictably, resulting in a reliable crash with potential for code execution. This issue has been fixed in version 1.8.7-r1."}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H","baseScore":7.3,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"HIGH"},"exploitabilityScore":2.5,"impactScore":4.7}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Primary","description":[{"lang":"en","value":"CWE-416"}]}],"references":[{"url":"https://github.com/saitoha/libsixel/releases/tag/v1.8.7-r1","source":"security-advisories@github.com"},{"url":"https://github.com/saitoha/libsixel/security/advisories/GHSA-j6m5-2cc7-3whc","source":"security-advisories@github.com"}]}}]}