CVE-2026-25961
HIGH 7.5EPSS 0.4%
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.
- CVSS v3.1
- 7.5 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H - CVSS v3.1
- 7.5 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H - EPSS
- 0.45% chance of exploitation in the next 30 days, 37th percentile
- Published
- 2026-02-09
- Updated
- 2026-02-10