{"id":"CVE-2026-23951","aliases":["EUVD-2026-4205","GHSA-hj4w-c5x8-p2hv"],"status":"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.","severity":{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00221,"percentile":0.12697,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-125","CWE-191","CWE-193"],"published":"2026-01-22T00:17:10Z","modified":"2026-10-28T02:31:12Z","products":[{"vendor":"sumatrapdfreader","product":"sumatrapdf"}],"references":[{"url":"https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-hj4w-c5x8-p2hv","tags":["x_refsource_CONFIRM","Exploit","Vendor Advisory","advisory"]},{"url":"https://github.com/sumatrapdfreader/sumatrapdf/blob/master/src/PalmDbReader.cpp","tags":["x_refsource_MISC","Product","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23951.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23951","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-23951","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.","status":"published","published":"2026-01-22T00:17:10.159Z","modified":"2026-01-22T21:44:27.284Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-125","CWE-191"],"updated_at":"2026-11-02T13:42:04.39372Z"}],"euvd":[{"id":"EUVD-2026-4205","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.","status":"published","published":"2026-01-22T00:17:10Z","modified":"2026-01-22T21:44:27Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T19:48:48.575559Z"}],"nvd":[{"id":"CVE-2026-23951","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.","status":"published","published":"2026-01-22T01:15:52.633Z","modified":"2026-06-17T10:22:20.423Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-125","CWE-191","CWE-193"],"updated_at":"2026-11-02T14:12:04.423757Z"}],"osv":[{"id":"CVE-2026-23951","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.","status":"published","published":"2026-01-22T00:17:10.159Z","modified":"2026-10-28T02:31:12.201713017Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-125","CWE-191"],"updated_at":"2026-11-02T15:44:59.079784Z"}]}}