CVE-2026-25961

HIGH

SumatraPDF <3.5.2 - RCE

Title source: llm

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.

Exploits (2)

github WORKING POC 10 stars
by XiaomingX · pythonpoc
https://github.com/XiaomingX/data-cve-poc-py-v1/tree/main/2026/CVE-2026-25961
nomisec WORKING POC
by mbanyamer · poc
https://github.com/mbanyamer/CVE-2026-25961-SumatraPDF-3.5.0---3.5.2-RCE

References (1)

Scores

CVSS v3 7.5
EPSS 0.0003
EPSS Percentile 6.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Details

CWE
CWE-295 CWE-494
Status published
Products (1)
sumatrapdfreader/sumatrapdf 3.5 - 3.5.2
Published Feb 09, 2026
Tracked Since Feb 18, 2026