CVE-2025-55200 BigBlueButton vulnerable to Stored XSS via name of user at Shared Notes

High 7.1 Published 9 Oct 2025 Updated 9 Oct 2025

Attackers can inject malicious scripts via usernames in Shared Notes, allowing code execution in admin sessions.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-55200?

CVE-2025-55200 is a high-severity cross-site scripting vulnerability in bigbluebutton, published on 9 Oct 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

BigBlueButton is an open-source virtual classroom. In versions prior to 3.0.13, the "Shared Notes" feature contains a Stored Cross-Site Scripting (XSS) vulnerability with the input location being the "Username" field and the output location on the "Shared Notes" page, when a user with a malicious username is editing content. This vulnerability allows a low-privileged user to execute arbitrary JavaScript in the context of higher-privileged users (e.g., Admins) who open the Shared Notes page. Version 3.0.13 fixes the issue.

Weakness: CWE-79

Which versions are affected by CVE-2025-55200?

It affects 1 product.

Products include Bigbluebutton Bigbluebutton.

How do I fix CVE-2025-55200?

No fix has been published for CVE-2025-55200 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-2025-55200 being exploited?

There is no known exploitation of CVE-2025-55200 in the wild and no public exploit code.

Sources

Also known as GHSA-9jv9-cjrm-grj2.