Denial-of-Service Vulnerability in BigBlueButton Open-Source Virtual Classroom
CVE-2025-61602

7.5HIGH

Key Information:

Vendor

Bigbluebutton

Status
Bigbluebutton
Vendor
CVE Published:
9 October 2025

What is CVE-2025-61602?

BigBlueButton, an open-source virtual classroom solution, has a flaw that allows authenticated users to disrupt chat functionality for all meeting participants. By sending a specially crafted reactionEmojiId through the GraphQL mutation chatSendMessageReaction, users can crash the chat feature. Affected versions are prior to 3.0.13, which includes a patch to resolve this issue. No alternative measures are known to mitigate this vulnerability.

Affected Version(s)

bigbluebutton < 3.0.13

References

https://github.com/bigbluebutton/bigbluebutton/security/a...
x_refsource_CONFIRM
https://github.com/bigbluebutton/bigbluebutton/pull/23651
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

JSON
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CVE-2025-61602 : Denial-of-Service Vulnerability in BigBlueButton Open-Source Virtual Classroom