What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-10-09 · updated 2026-10-19
• Weakness: CWE-79

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.

Affected products

• bigbluebutton: before 3.0.13 — fixed in 3.0.13

How to fix

Upgrade to a fixed version: bigbluebutton 3.0.13. Check the vendor advisory for mitigations.

References

• https://github.com/bigbluebutton/bbb-pads/pull/67
• https://github.com/bigbluebutton/bbb-pads/releases/tag/v1.5.4
• https://github.com/bigbluebutton/bigbluebutton/pull/23693
• https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-9jv9-cjrm-grj2

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