CVE-2025-51691: XSS (CVSS 6.1)

Description

Cross-Site Scripting (XSS) vulnerability found in MarkTwo commit e3a1d3f90cce4ea9c26efcbbf3a1cbfb9dcdb298 (May 2025) allows a remote attacker to execute arbitrary code via a crafted script input to the editor interface. The application does not properly sanitize user-supplied Markdown before rendering it. Successful exploitation could lead to session hijacking, credential theft, or arbitrary client-side code execution in the context of the victim's browser.

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CVSS v3.1 Score

6.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://github.com/0x72303074/CVE-Disclosures/tree/main/MarkTwo%20Markdown%20Editor/CVE-2025-51691 https://github.com/anthonygarvan/marktwo https://marktwo.app/try-it-now

Frequently Asked Questions

What is CVE-2025-51691? +

Cross-Site Scripting (XSS) vulnerability found in MarkTwo commit e3a1d3f90cce4ea9c26efcbbf3a1cbfb9dcdb298 (May 2025) allows a remote attacker to execute arbitrary code via a crafted script input to the editor interface. The application does not properly sanitize user-supplied Markdown before rendering it. Successful exploitation could lead to session hijacking, credential theft, or arbitrary client-side code execution in the context of the victim's browser. It has a CVSS v3.1 base score of 6.1 (MEDIUM).

How severe is CVE-2025-51691? +

CVE-2025-51691 has a CVSS v3.1 score of 6.1 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

How do I check if I'm vulnerable to CVE-2025-51691? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2025-51691