{"id":"CVE-2026-23951","state":"PUBLISHED","title":"SumatraPDF's Integer Underflow in PalmDbReader Leads to Crash","description":"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.","publishedAt":"2026-01-22T00:17:10.159Z","updatedAt":"2026-01-22T21:44:27.284Z","severity":{"score":5.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["sumatrapdfreader sumatrapdf"],"affected":[{"vendor":"sumatrapdfreader","product":"sumatrapdf","versions":[{"version":"<= 3.5.2rel","status":"affected"}]}],"references":["https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-hj4w-c5x8-p2hv","https://github.com/sumatrapdfreader/sumatrapdf/blob/master/src/PalmDbReader.cpp"],"weaknesses":["CWE-125","CWE-191"],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/23xxx/CVE-2026-23951.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23951","state":"PUBLISHED","datePublished":"2026-01-22T00:17:10.159Z","dateUpdated":"2026-01-22T21:44:27.284Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-01-19T14:49:06.312Z"},"containers":{"cna":{"title":"SumatraPDF's Integer Underflow in PalmDbReader Leads to Crash","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"sumatrapdfreader","product":"sumatrapdf","versions":[{"version":"<= 3.5.2rel","status":"affected"}]}],"references":[{"url":"https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-hj4w-c5x8-p2hv","name":"https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-hj4w-c5x8-p2hv","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/sumatrapdfreader/sumatrapdf/blob/master/src/PalmDbReader.cpp","name":"https://github.com/sumatrapdfreader/sumatrapdf/blob/master/src/PalmDbReader.cpp","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":5.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","description":"CWE-125: Out-of-bounds Read","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-191","lang":"en","description":"CWE-191: Integer Underflow (Wrap or Wraparound)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-01-22T00:17:10.159Z"},"source":{"advisory":"GHSA-hj4w-c5x8-p2hv","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-01-22T21:44:16.346671Z","id":"CVE-2026-23951","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":"2026-01-22T21:44:27.284Z"}}]}}}