{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-06-13T23:12:03.383","vulnerabilities":[{"cve":{"id":"CVE-2026-33020","sourceIdentifier":"security-advisories@github.com","published":"2026-04-14T22:16:30.543","lastModified":"2026-04-23T14:47:18.660","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow which leads to a heap buffer overflow via sixel_frame_convert_to_rgb888() in frame.c, where allocation size and pointer offset computations for palettised images (PAL1, PAL2, PAL4) are performed using int arithmetic before casting to size_t. For images whose pixel count exceeds INT_MAX / 4, the overflow produces an undersized heap allocation for the conversion buffer and a negative pointer offset for the normalization sub-buffer, after which sixel_helper_normalize_pixelformat() writes the full image data starting from the invalid pointer, causing massive heap corruption confirmed by ASAN. An attacker providing a specially crafted large palettised PNG can corrupt the heap of the victim process, resulting in a reliable crash and potential arbitrary code execution.\nThis 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:R/S:U/C:N/I:H/A:H","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.2}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-122"},{"lang":"en","value":"CWE-190"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:saitoha:libsixel:*:*:*:*:*:*:*:*","versionEndExcluding":"1.8.7-r1","matchCriteriaId":"E16EAA6A-544F-4D16-829D-1B7C9979EA6A"}]}]}],"references":[{"url":"https://github.com/saitoha/libsixel/releases/tag/v1.8.7-r1","source":"security-advisories@github.com","tags":["Release Notes"]},{"url":"https://github.com/saitoha/libsixel/security/advisories/GHSA-2xgm-4x47-2x2p","source":"security-advisories@github.com","tags":["Exploit","Vendor Advisory"]},{"url":"https://github.com/saitoha/libsixel/security/advisories/GHSA-2xgm-4x47-2x2p","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","tags":["Exploit","Vendor Advisory"]}]}}]}