CVE-2026-25961
Insecure Update Mechanism in SumatraPDF Allows Remote Code Execution
Publication date: 2026-02-09
Last updated on: 2026-02-20
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| sumatrapdfreader | sumatrapdf | From 3.5 (inc) to 3.5.2 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-494 | The product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code. |
| CWE-295 | The product does not validate, or incorrectly validates, a certificate. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability affects SumatraPDF versions 3.5.0 through 3.5.2. The update mechanism in these versions disables TLS hostname verification and executes installers without verifying their digital signatures. As a result, a network attacker who has any valid TLS certificate, such as one from Let's Encrypt, can intercept the update check request, inject a malicious installer URL, and cause the application to execute arbitrary code.
How can this vulnerability impact me? :
This vulnerability can lead to arbitrary code execution on your system if exploited. An attacker can intercept the update process, deliver a malicious installer, and run harmful code with the privileges of the user running SumatraPDF. This can result in system compromise, data theft, or further malware installation.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know