CVE-2026-107737

medium

Description

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, and in pre-release 3.7.0.20369 when WebView2 is absent or cannot initialize, ParseProtoUrl() accepts the signed host component of an its:// URL and FindHtmlWindowById() uses it directly as an index into gHtmlWindows. Opening a crafted CHM through the IE fallback backend with a negative or otherwise out-of-range window identifier can cause an out-of-bounds pointer read followed by an invalid object callback dereference and process termination. No fixed version is available as of this review.

References

https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-8p34-f32f-7rmq

https://github.com/sumatrapdfreader/sumatrapdf/commit/596c7e26e983549a77a3a38cae1147ab73792929

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-95412

Details

Source: Mitre, NVD

Published: 2026-10-08

Updated: 2026-10-13

Risk Information

CVSS v2

Base Score: 5.8

Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:N/A:P

Severity: Medium

CVSS v3

Base Score: 7.1

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H

Severity: High

CVSS v4

Base Score: 5.7

Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Severity: Medium

EPSS

EPSS: 0.00182