CVE-2025-61602

BigBlueButton is an open-source virtual classroom. A denial-of-service (DoS) vulnerability in versions prior to 3.0.13 allows any authenticated user to crash the chat functionality for all participants in a meeting by sending a malformed `reactionEmojiId` in the GraphQL mutation `chatSendMessageReaction`. Version 3.0.13 contains a patch. No known workarounds are available.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 33% of CVEs (scores of 2026-10-25)

CWE

CWE-703

Published

2025-10-09

Modified

2026-10-19

Record from

the NVD, synced 2026-10-19

Affected

• bigbluebutton:bigbluebutton

References

• https://github.com/bigbluebutton/bigbluebutton/pull/23651
• https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-45j2-m26c-3pcm
• https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-45j2-m26c-3pcm

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