SumatraPDF Update MITM -> Arbitrary Code Execution_CVE-2026-25961

7.5 / 10

HIGH

CVSS: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.

Basic Information

ID CVE-2026-25961

Source GitHub_M

Published Feb 9, 2026 at 21:34

Affected Product

Vendor sumatrapdfreader

Product sumatrapdf

Version >= 3.5.0, <= 3.5.2

Affected Versions sumatrapdfreader sumatrapdf >= 3.5.0, <= 3.5.2

CWE Classification

CWE-295 CWE-494

References

github.com /sumatrapdfreader/sumatrapdf/security/advisories/GHSA-xpm2-rr5m-x96q

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    "published": "2026-02-09T21:34:05.203Z",
    "modified": "2026-02-09T21:34:05.203Z",
    "type": "cve",
    "title": "SumatraPDF Update MITM -> Arbitrary Code Execution",
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