CVE-2022-31065: Cross site scripting vulnerability for private chat in bigbluebutton

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-06-27 · updated 2026-06-17
Weakness: CWE-79

Description

BigBlueButton is an open source web conferencing system. In affected versions an attacker can embed malicious JS in their username and have it executed on the victim's client. When a user receives a private chat from the attacker (whose username contains malicious JavaScript), the script gets executed. Additionally when the victim receives a notification that the attacker has left the session. This issue has been patched in version 2.4.8 and 2.5.0. There are no known workarounds for this issue.

Affected products

bigbluebutton: from 2.4 before 2.4.8; 2.3.0, 2.4.9, 2.5-alpha1, 2.5-alpha2, 2.5-alpha3, 2.5-alpha4 (+8) — fixed in 2.4.8

How to fix

Upgrade to a fixed version: bigbluebutton 2.4.8. Check the vendor advisory for mitigations.

References

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