Vulnerability · Published Oct 8, 2026 · Assigned by GitHub_M
CVE-2026-107731SumatraPDF: LIT parser range-validation flaws cause invalid-pointer reads and denial of service
Medium 5.5
In plain English
A medium-severity out-of-bounds read in sumatrapdf from sumatrapdfreader. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 1% of all known vulnerabilities).
Official description
SumatraPDF is a multi-format reader for Windows. In 3.7.0.22298, four independently reachable range-validation variants in src/LitDoc.cpp allow file-controlled offsets and sizes to overflow, narrow to negative values, or wrap before incomplete bounds checks. The affected calculations include contentOffset, the directory expression dirOff64 + dirLen64, and the decoded-section offset + size, along with secondary-header range handling. Opening a crafted LIT file that reaches one of these variants can cause invalid pointer reads and deterministic application termination. No broader impact is claimed beyond the advisory-supported conditions. No fixed version is available as of this review.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| sumatrapdfreader | sumatrapdf | <= 3.7.0.22298 |
Weakness: CWE-125 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H