BigBlueButton version 2.4.7 (or earlier) is vulnerable to stored Cross-Site Scripting (XSS) in the private chat functionality. A threat actor could inject JavaScript payload in his/her username. The payload gets executed in the browser of the victim each time the attacker sends a private message to the victim or when notification about the attacker leaving room is displayed.
Conclusion & alert: CVE-2022-27238 is rated Low Risk (32.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.38%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.19% | 0.38% | +0.19% |
| 2 | 2025-07-07 | 0.28% | 0.19% | -0.08% |
| 3 | 2025-06-25 | — | 0.28% | — |
Full EPSS history (6 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.4 | 3.1 | MEDIUM |
|
2.3 | 2.7 | [email protected] |
| 3.5 | 2.0 | LOW |
|
6.8 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| bigbluebutton | bigbluebutton | <= 2.4.7 | cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://www.mgm-sp.com/en/cve-2022-27238-bigbluebutton-xss/ | Third Party Advisory |