Vulnerability · Published May 18, 2026 · Assigned by GitHub_M
CVE-2026-27737BigBlueButton has Stored XSS in bbb-playback replay
Medium 6.5
In plain English
A medium-severity cross-site scripting in bbb-playback from bigbluebutton. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities).
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.3%top 82.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| bigbluebutton | bigbluebutton | < 3.0.19 |
| blindsidenetworks | scalite | < 1.7.0 |
| bigbluebutton | bbb-playback | < 5.4.3 |
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
References
- https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-8vv7-vj94-q2pv x_refsource_CONFIRM
- https://github.com/bigbluebutton/bbb-playback/commit/09e89bfe4ff8488b68c3ff040d3081e419dc89b1 x_refsource_MISC
- https://github.com/bigbluebutton/bigbluebutton/commit/69f45aa1b963dc7d80179d0155acc670aec5c4fc x_refsource_MISC
- https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.19 x_refsource_MISC
- https://github.com/blindsidenetworks/scalelite/releases/tag/v1.7.0 x_refsource_MISC