CVE-2026-23951

EUVD-2026-4205
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5.5 MEDIUM
LOCAL
LOW
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
GitHub_MCNA
5.5 MEDIUM
LOCAL
LOW
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Affected Products (NVD)
VendorProductVersion
sumatrapdfreadersumatrapdf
-
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://github.com/sumatrapdfreader/sumatrapdf/blob/master/src/PalmDbReader.cpp
https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-hj4w-c5x8-p2hv