CVE-2025-51691 Cross-site scripting in n/a
Remote attackers can execute arbitrary code via unsanitized Markdown input in the MarkTwo editor, leading to session hijacking or credential theft.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-51691?
CVE-2025-51691 is a medium-severity cross-site scripting vulnerability in n/a, published on 13 Aug 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2025-51691?
How do I fix CVE-2025-51691?
No fix has been published for CVE-2025-51691 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2025-51691 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-51691 exists.
Sources
Also known as GHSA-j294-xfq6-8863.