CVE-2026-115758

CVSS 8.2 (high) · published 2026-11-04

SumatraPDF is a multi-format reader for Windows. In version 3.6.1 and earlier, HttpGet() in src/base/Http_win.cpp unconditionally passes INTERNET_FLAG_IGNORE_CERT_CN_INVALID to WinINet, disabling hostname matching for HTTPS update metadata and crash-symbol requests while retaining certificate-chain validation. A network-positioned attacker with a Windows-trusted certificate for an attacker-controlled domain can impersonate the project's update host, inject promo text and a clickable URL before update metadata validation, and provide an attacker-controlled archive to ExtractSymbols(). Installer replacement is not directly possible because HttpGetToFile() validates TLS and MaybeStartUpdateDownload() restricts the download host. No fixed version is available as of this review.

Weakness: CWE-297

Source: NVD CVE-2026-115758

References

• https://github.com/sumatrapdfreader/sumatrapdf/commit/bd30134175e897dd5ed0d7fd14acce52eeca7183
• https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-mjwr-9w29-jp96

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