{"id":"CVE-2026-23951","summary":"SumatraPDF's Integer Underflow in PalmDbReader Leads to Crash","details":"SumatraPDF is a multi-format reader for Windows. All versions contain an off-by-one error in the validation code that only triggers with exactly 2 records, causing an integer underflow in the size calculation. This bug exists in PalmDbReader::GetRecord when opening a crafted Mobi file, resulting in an out-of-bounds heap read that crashes the app. There are no published fixes at the time of publication.","aliases":["GHSA-hj4w-c5x8-p2hv"],"modified":"2026-08-12T03:51:30.378637016Z","published":"2026-01-22T00:17:10.159Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-125","CWE-191"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23951.json"},"references":[{"type":"WEB","url":"https://github.com/sumatrapdfreader/sumatrapdf/blob/master/src/PalmDbReader.cpp"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23951.json"},{"type":"ADVISORY","url":"https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-hj4w-c5x8-p2hv"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23951"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/sumatrapdfreader/sumatrapdf","events":[{"introduced":"0"},{"last_affected":"646d1feddcc80b3b51072c5b27a1446487904175"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"last_affected":"3.5.2rel"}],"source":"AFFECTED_FIELD"}}],"versions":["3.5.2rel","3.5.1rel","3.5rel","3.2","3.1.2rel","3.0split","2.5split","2.4split","2.3split","2.2split","2.1split","2.0split","1.9split","1.8split","1.7split","1.6split","1.5split","1.4split"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23951.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"}]}