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.

Project Subscriptions

Vendors Products
Sumatrapdfreader Subscribe
Sumatrapdf Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 10 Feb 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Tue, 10 Feb 2026 12:45:00 +0000

Type Values Removed Values Added
First Time appeared Sumatrapdfreader
Sumatrapdfreader sumatrapdf
Vendors & Products Sumatrapdfreader
Sumatrapdfreader sumatrapdf

Mon, 09 Feb 2026 21:45:00 +0000

Type Values Removed Values Added
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.
Title SumatraPDF Update MITM -> Arbitrary Code Execution
Weaknesses CWE-295
CWE-494
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-10T15:57:28.303Z

Reserved: 2026-02-09T17:13:54.066Z

Link: CVE-2026-25961

cve-icon Vulnrichment

Updated: 2026-02-10T15:32:02.622Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-02-09T22:16:04.750

Modified: 2026-02-10T15:22:54.740

Link: CVE-2026-25961

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-02-10T11:34:59Z

Weaknesses