CVE-2026-107735: Sumatrapdfreader Sumatrapdf

Medium severity, CVSS 5.4. EPSS: 0.1% chance of exploitation in the next 30 days.

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, InitializePolicies() starts the sumatrapdfrestrict.ini path with gPolicyRestrictions set to Perm::All and only ORs permission bits, so the INI file never revokes permissions. Deploying SumatraPDF with this INI file, including a malformed file or zero-valued permission settings, can silently bypass configured disk, network, printing, registry, clipboard, preference, and fullscreen restrictions. The -restrict command-line path works correctly and is not affected. No fixed version is available as of this review.

Affected products

• Sumatrapdfreader Sumatrapdf: up to and including 3.6.1

Published 2026-10-08. Last modified 2026-10-09.