CVE-2025-10255 Ascensio System SIA OnlyOffice Comment Messages.aspx cross site scripting
Remote attackers can inject malicious scripts into OnlyOffice comment messages, potentially leading to code execution or account takeover.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-10255?
CVE-2025-10255 is a medium-severity cross-site scripting vulnerability in Ascensio System SIA OnlyOffice, published on 11 Sep 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
A vulnerability was determined in Ascensio System SIA OnlyOffice up to 12.7.0. Impacted is an unknown function of the file /Products/Projects/Messages.aspx of the component Comment Handler. Executing manipulation can lead to cross site scripting. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized. The vendor was informed early about this issue and replied: "We are already working on this case, and the issues will be resolved in one of the upcoming patches."
Which versions are affected by CVE-2025-10255?
How do I fix CVE-2025-10255?
No fix has been published for CVE-2025-10255 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-2025-10255 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-10255 exists.
Sources
Also known as GHSA-x97w-4gg4-c3fh.