All vulnerabilities
CVE-2026-107738GHSA-33jg-vxm6-8mxx

SumatraPDF: Untrusted binary record offset used without lower-bound validation

sumatrapdfreader sumatrapdf
Open in ThreatlineRecord JSON
CVSS
6.8Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.12%Chance of exploitation activity in the next 30 days, higher than 1% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published8 Oct 2026Updated 14 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Description

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, ChmFile::GetCharZ() narrows file-controlled unsigned string offsets from /#WINDOWS and /#IVB to signed integers without a lower-bound check. An offset that becomes negative can make the function read before the /#STRINGS buffer, causing deterministic application termination. No broader impact is claimed beyond the advisory-supported conditions. No fixed version is available as of this review.

Text from CVE List

Affected versions 1

  • sumatrapdfaffected: <= 3.6.1CVE List

References 2