BigBlueButton has Stored XSS in bbb-playback replay
Priority LOW 28CWE-79Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00257 17th percentileScored 2026-11-07
Fix Fixed bigbluebutton (bigbluebutton): 3.0.19scalite (blindsidenetworks): 1.7.0+1 more product
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| bigbluebutton | bigbluebutton | before 3.0.19 | 3.0.19 | Patch available | CNA |
| blindsidenetworks | scalite | before 1.7.0 | 1.7.0 | Patch available | CNA |
| bigbluebutton | bbb-playback | before 5.4.3 | 5.4.3 | Patch available | CNA |
- bigbluebutton Vendorbigbluebutton Affected before 3.0.19 Fixed in 3.0.19 Patch available CNA
- scalite Vendorblindsidenetworks Affected before 1.7.0 Fixed in 1.7.0 Patch available CNA
- bbb-playback Vendorbigbluebutton Affected before 5.4.3 Fixed in 5.4.3 Patch available CNA
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:* | — | — | bigbluebutton |
- cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:* Versions — — ·bigbluebutton
Remediation
- Fix · CNA bigbluebutton (bigbluebutton) Fixed in 3.0.19
- Fix · CNA scalite (blindsidenetworks) Fixed in 1.7.0
- Fix · CNA bbb-playback (bigbluebutton) Fixed in 5.4.3
Timeline
- 2026-10-02 Threatist record created from CVE-2026-27737
References
Other 5
- https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-8vv7-vj94-q2pv
- https://github.com/bigbluebutton/bbb-playback/commit/09e89bfe4ff8488b68c3ff040d3081e419dc89b1
- https://github.com/bigbluebutton/bigbluebutton/commit/69f45aa1b963dc7d80179d0155acc670aec5c4fc
- https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.19
- https://github.com/blindsidenetworks/scalelite/releases/tag/v1.7.0
More bigbluebutton vulnerabilities
- TI-2026-21873 BigBlueButton: Exposed ClamAV port enables Denial of Service CVSS 3.1HIGH 8.2
- TI-2025-38047 BigBlueButton vulnerable to Chat DoS via invalid reactionEmojiId CVSS 3.1HIGH 7.5
- TI-2025-38046 BigBlueButton vulnerable to DoS via PollSubmitVote GraphQL mutation CVSS 3.1HIGH 7.5
- TI-2022-13109 Cross site scripting in username that will trigger by sending chat CVSS 3.1MEDIUM 6.5
- TI-2020-09954 BigBlueButton before 2.2.6 allows remote attackers to read arbitrary files because the… CVSS 3.1CRITICAL 9.8
- TI-2022-16454 BigBlueButton Greenlight Open Redirect vulnerability CVSS 3.1CRITICAL 9.1
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences