---
id: CVE-2026-107731
title: SumatraPDF is a multi-format reader for Windows
summary: >-
  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 inco…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
cwe:
  - CWE-125
published: '2026-10-08'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T23:16:58.833'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-107731'
references:
  - url: >-
      https://github.com/sumatrapdfreader/sumatrapdf/commit/5d43b8cf9c45335ffd47e616bfa27648f17d0b63
    label: security-advisories@github.com
  - url: >-
      https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-753j-hx3p-xm9g
    label: security-advisories@github.com
tags:
  - nvd
ingestedAt: '2026-10-09T00:19:50.970Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.