---
cve: "CVE-2026-46355"
severity: "HIGH"
cvss: 7.1
epss: "19.7%"
vendor: "bigbluebutton"
kev: false
exploited: false
published: "2026-08-20 22:17:19"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-04T07:00:11+02:00"
---

# CVE-2026-46355

> 7.1 HIGH · 🧪 PoC

## Beschreibung

BigBlueButton is an open-source virtual classroom. Prior to 3.0.23, BigBlueButton exposed /bigbluebutton/api/handleJoinExistingUser through bigbluebutton-web/grails-app/controllers/org/bigbluebutton/web/controllers/ApiController.groovy. A requester able to supply an existingUserID for an active participant could reuse that participant's session and impersonate the participant in the same meeting because handleJoinExistingUser was a routable controller action rather than a private helper. This issue is fixed in version 3.0.23.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Gering | warn |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- 972b04e474e195cbd708b5b3f0485fe528a1a85b (Commit)
- d32178587c1e623be2b87992b109af4a86c7a95e (Commit)

## Referenzen

- <https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-38fw-2gq7-ccgr>
- <https://github.com/bigbluebutton/bigbluebutton/commit/972b04e474e195cbd708b5b3f0485fe528a1a85b>
- <https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.23>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-46355) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_