VULNERABILITY INTELLIGENCE

CVE-2026-25961

CVSS score7.5 HIGH
EPSS probability0.44%
CISA KEVNot currently listed
Published2026-02-09
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Description

SumatraPDF is a multi-format reader for Windows. In 3.5.0 through 3.5.2, SumatraPDF's update mechanism disables TLS hostname verification (INTERNET_FLAG_IGNORE_CERT_CN_INVALID) and executes installers without signature checks. A network attacker with any valid TLS certificate (e.g., Let's Encrypt) can intercept the update check request, inject a malicious installer URL, and achieve arbitrary code execution.

Weakness classification

  • security-advisories@github.com: CWE-295
  • nvd@nist.gov: CWE-494

Primary references