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.
History

Thu, 22 Jan 2026 23:00:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 22 Jan 2026 00:45:00 +0000

Type Values Removed Values Added
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.
Title SumatraPDF's Integer Underflow in PalmDbReader Leads to Crash
Weaknesses CWE-125
CWE-191
References
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-01-22T00:17:10.159Z

Updated: 2026-01-22T21:44:27.284Z

Reserved: 2026-01-19T14:49:06.312Z

Link: CVE-2026-23951

cve-icon Vulnrichment

Updated: 2026-01-22T21:44:22.321Z

cve-icon NVD

Status : Received

Published: 2026-01-22T01:15:52.633

Modified: 2026-01-22T01:15:52.633

Link: CVE-2026-23951

cve-icon Redhat

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