{"id":"CVE-2026-55491","aliases":["EUVD-2026-63682","GHSA-57p5-c888-74f9"],"status":"published","title":"BigBlueButton: Stored XSS in Screenshare Recording Playback via Unescaped Meeting Name","description":"BigBlueButton is an open-source virtual classroom. Prior to 3.0.29, BigBlueButton failed to escape meetingName in record-and-playback/screenshare/playback/index.html.erb when generating the screenshare playback format. A low-privileged user could store a crafted meeting name that embedded script content, and the script executed in another user's browser when that user replayed the recording. This issue is fixed in version 3.0.29.","severity":{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00289,"percentile":0.21692,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2026-08-20T21:35:42Z","modified":"2026-10-28T11:14:52Z","products":[{"vendor":"bigbluebutton","product":"bigbluebutton"}],"references":[{"url":"https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-57p5-c888-74f9","tags":["x_refsource_CONFIRM","advisory"]},{"url":"https://github.com/bigbluebutton/bigbluebutton/commit/a53f2b92022388bfa4109d3136d1f3a932404b1b","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.29","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55491.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55491","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-55491","title":"BigBlueButton: Stored XSS in Screenshare Recording Playback via Unescaped Meeting Name","description":"BigBlueButton is an open-source virtual classroom. Prior to 3.0.29, BigBlueButton failed to escape meetingName in record-and-playback/screenshare/playback/index.html.erb when generating the screenshare playback format. A low-privileged user could store a crafted meeting name that embedded script content, and the script executed in another user's browser when that user replayed the recording. This issue is fixed in version 3.0.29.","status":"published","published":"2026-08-20T21:35:42.546Z","modified":"2026-08-21T15:50:11.735Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:20:12.260247Z"}],"euvd":[{"id":"EUVD-2026-63682","description":"BigBlueButton is an open-source virtual classroom. Prior to 3.0.29, BigBlueButton failed to escape meetingName in record-and-playback/screenshare/playback/index.html.erb when generating the screenshare playback format. A low-privileged user could store a crafted meeting name that embedded script content, and the script executed in another user's browser when that user replayed the recording. This issue is fixed in version 3.0.29.","status":"published","published":"2026-08-20T21:35:42Z","modified":"2026-08-21T15:50:11Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T18:01:37.531944Z"}],"nvd":[{"id":"CVE-2026-55491","description":"BigBlueButton is an open-source virtual classroom. Prior to 3.0.29, BigBlueButton failed to escape meetingName in record-and-playback/screenshare/playback/index.html.erb when generating the screenshare playback format. A low-privileged user could store a crafted meeting name that embedded script content, and the script executed in another user's browser when that user replayed the recording. This issue is fixed in version 3.0.29.","status":"published","published":"2026-08-20T22:17:22.347Z","modified":"2026-10-26T10:10:00.14Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:40.302911Z"}],"osv":[{"id":"CVE-2026-55491","title":"BigBlueButton: Stored XSS in Screenshare Recording Playback via Unescaped Meeting Name","description":"BigBlueButton is an open-source virtual classroom. Prior to 3.0.29, BigBlueButton failed to escape meetingName in record-and-playback/screenshare/playback/index.html.erb when generating the screenshare playback format. A low-privileged user could store a crafted meeting name that embedded script content, and the script executed in another user's browser when that user replayed the recording. This issue is fixed in version 3.0.29.","status":"published","published":"2026-08-20T21:35:42.546Z","modified":"2026-10-28T11:14:52.580609598Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:45:11.22012Z"}]}}