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CVE-2026-27737

BigBlueButton has Stored XSS in bbb-playback replay

Published: May 18, 2026Updated: May 19, 2026 Sources: CVE List NVDCWE-79
NVD MITRE
6.5CVSSMEDIUM
EPSS Score
0.3%
Top 83.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

Description

BigBlueButton is an open-source virtual classroom. In versions prior to 3.0.19, the recording playback (presentation format) was not sanitizing user's input in public chat. This allowed for a malicious actor to craft and carry out a targeted XSS attack, activated on anyone replaying the recording. This issue has been fixed 3.0.19.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:NS:UC:NI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:HIntegrity
High
A:NAvailability
None
Open in CVSS calculator →

Weaknesses

CWE-79

Affected Products

bigbluebuttonbigbluebutton
On-premWeb App
Communications / video-conferencing
scaliteblindsidenetworks
SaaS
Communications / video-conferencing
bbb-playbackbigbluebutton
On-prem
Communications / video-conferencing
bigbluebuttonoss-projectCommunicationsaka bbb
blindsidenetworkscommercialCommunications

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

MITRE ATT&CK

2 techniques
Execution
Initial Access
View detailed technique mapping

References

https://github.com/bigbluebutton/bbb-playback/commit/09e89bfe4ff8488b68c3ff040d3081e419dc89b1
github.com
https://github.com/bigbluebutton/bigbluebutton/commit/69f45aa1b963dc7d80179d0155acc670aec5c4fc
github.com
https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.19
github.com
and 2 more references View all →

Timeline

Published
May 18, 2026
Last Updated
May 19, 2026

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