CVE-2026-27737

BigBlueButton has Stored XSS in bbb-playback replay

Published: May 18, 2026Updated: Jul 24, 2026 Sources: CVE List NVDCWE-79

6.5MEDIUM

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.

No summary for this CVE yet.

CVSS Vector Breakdown

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

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Weaknesses

CWE-79

Affected Products

bigbluebutton

oss-projectaka bbb

bigbluebuttonOn-premWeb App

Communications / video-conferencing

bbb-playbackOn-premWeb App

Communications / video-conferencing

blindsidenetworks

commercial

scaliteSaaS

Communications / video-conferencing

Exploitability

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

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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques

Execution

Initial Access

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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 →

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