web/controllers/ApiController.groovy in BigBlueButton before 2.2.29 lacks certain parameter sanitization, as demonstrated by accepting control characters in a user name.
Conclusion & alert: CVE-2020-28954 is rated Moderate Risk (44.8/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.23%). Mandatory action: Review affected assets and schedule remediation.
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 | 0.38% | 1.23% | +0.85% |
| 2 | 2025-03-30 | 0.34% | 0.38% | +0.05% |
| 3 | 2025-03-29 | — | 0.34% | — |
Full EPSS history (10 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.3 | 3.1 | MEDIUM |
|
3.9 | 1.4 | [email protected] |
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| bigbluebutton | bigbluebutton | < 2.2.29 | cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://github.com/bigbluebutton/bigbluebutton/commit/5c911ddeec4493f40f42e2f137800ed4692004a4 | Patch Third Party Advisory |
| https://github.com/bigbluebutton/bigbluebutton/commit/e59bcd0c33a6a3203c011faa8823ba2cac1e4f37 | Patch Third Party Advisory |
| https://github.com/bigbluebutton/bigbluebutton/compare/v2.2.28...v2.2.29 | Release Notes Third Party Advisory |
| https://github.com/bigbluebutton/bigbluebutton/issues/10818 | Third Party Advisory |