CVE-2025-61602: Bigbluebutton

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Bigbluebutton Bigbluebutton: before 3.0.13 (fixed in 3.0.13)

Published 2025-10-09. Last modified 2026-06-17.