BigBlueButton Stored Cross-site Scripting vulnerability at Guest Lobby
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
- Low · Low · Low
- 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. Prior to versions 2.6.11 and 2.7.0-beta.3, Guest Lobby was vulnerable to cross-site scripting when users wait to enter the meeting due to inserting unsanitized messages to the element using unsafe innerHTML. Text sanitizing was added for lobby messages starting in versions 2.6.11 and 2.7.0-beta.3. There are no known workarounds.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0047 40th percentileScored 2026-11-07
Fix Fixed bigbluebutton (bigbluebutton): 2.6.11, 2.7.0-beta.3
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 2.6.11; 2.7.0-alpha.1 to before 2.7.0-beta.3 | 2.6.11, 2.7.0-beta.3 | Patch available | CNA |
- bigbluebutton Vendorbigbluebutton Affected before 2.6.11; 2.7.0-alpha.1 to before 2.7.0-beta.3 Fixed in 2.6.11, 2.7.0-beta.3 Patch available CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:* | before 2.6.11 | Vulnerable | bigbluebutton |
| cpe:2.3:a:bigbluebutton:bigbluebutton:2.7.0:alpha1:*:*:*:*:*:* | 2.7.0 alpha1 | Vulnerable | bigbluebutton |
| cpe:2.3:a:bigbluebutton:bigbluebutton:2.7.0:alpha2:*:*:*:*:*:* | 2.7.0 alpha2 | Vulnerable | bigbluebutton |
| cpe:2.3:a:bigbluebutton:bigbluebutton:2.7.0:alpha3:*:*:*:*:*:* | 2.7.0 alpha3 | Vulnerable | bigbluebutton |
| cpe:2.3:a:bigbluebutton:bigbluebutton:2.7.0:beta1:*:*:*:*:*:* | 2.7.0 beta1 | Vulnerable | bigbluebutton |
| cpe:2.3:a:bigbluebutton:bigbluebutton:2.7.0:beta2:*:*:*:*:*:* | 2.7.0 beta2 | Vulnerable | bigbluebutton |
- cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:* Versions before 2.6.11 Vulnerable ·bigbluebutton
- cpe:2.3:a:bigbluebutton:bigbluebutton:2.7.0:alpha1:*:*:*:*:*:* Versions 2.7.0 alpha1 Vulnerable ·bigbluebutton
- cpe:2.3:a:bigbluebutton:bigbluebutton:2.7.0:alpha2:*:*:*:*:*:* Versions 2.7.0 alpha2 Vulnerable ·bigbluebutton
- cpe:2.3:a:bigbluebutton:bigbluebutton:2.7.0:alpha3:*:*:*:*:*:* Versions 2.7.0 alpha3 Vulnerable ·bigbluebutton
- cpe:2.3:a:bigbluebutton:bigbluebutton:2.7.0:beta1:*:*:*:*:*:* Versions 2.7.0 beta1 Vulnerable ·bigbluebutton
- cpe:2.3:a:bigbluebutton:bigbluebutton:2.7.0:beta2:*:*:*:*:*:* Versions 2.7.0 beta2 Vulnerable ·bigbluebutton
Remediation
- Fix · CNA bigbluebutton (bigbluebutton) Fixed in 2.6.11, 2.7.0-beta.3
Timeline
- 2026-10-02 Threatist record created from CVE-2023-43797
References
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-2020-16722 BigBlueButton through 2.2.28 uses Ghostscript for processing of uploaded EPS documents… CVSS 3.1CRITICAL 9.8
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences