VulnerabilityDeferred

CVE-2026-107738

SumatraPDF is a multi-format reader for Windows.

MEDIUM 6.8EPSS 0.12%

Does this matter?

Lower severity and a low EPSS score (0.12%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0: 6.8 MEDIUMCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.12% probability · 2th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-125
Source: security-advisories@github.com

EPSS trend

EPSS moved from 0.1% on 9 October 2026 to 0.1% on 26 October 2026.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.