CVE-2026-88361

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

SumatraPDF 3.6.1 contains an integer overflow vulnerability in EngineMupdf::BuildPageLabelRec() when parsing PDF PageLabels /Nums entries.

Published 2026-09-24. Last modified 2026-09-25.