VULNERABILITY INTELLIGENCE

CVE-2026-23951

CVSS score5.5 MEDIUM

EPSS probability0.22%

CISA KEVNot currently listed

Published2026-01-22

Last modified2026-06-17

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.