CVE-2026-25961
7.5 · HIGHOverview
CVE-2026-25961 is a high-severity vulnerability affecting sumatrapdfreader sumatrapdf. It was published on February 9, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from sumatrapdfreader. Update sumatrapdf to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| sumatrapdfreader | sumatrapdf | 3.5 | Affected |
Frequently Asked Questions
What is CVE-2026-25961?
CVE-2026-25961 is a high-severity vulnerability affecting sumatrapdfreader sumatrapdf. It was published on February 9, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2026-25961?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-25961?
Check the references section for vendor advisories and patches from sumatrapdfreader. Update sumatrapdf to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-25961?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-25961 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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