High severity · published Oct 9, 2025
CVE-2025-61602
BigBlueButton vulnerable to Chat DoS via invalid reactionEmojiId
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 33% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BI
bigbluebutton · bigbluebutton
< 3.0.13 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-61602
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-61602
Issue Tracking
https://github.com/bigbluebutton/bigbluebutton/pull/23651
Exploit
https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-45j2-m26c-3pcm
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