{"id":"CVE-2026-55491","title":"BigBlueButton is an open-source virtual classroom","summary":"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 u…","severity":"medium","cvss":5.4,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","cwe":["CWE-79"],"published":"2026-08-20","updated":"2026-09-16","sourceUpdated":"2026-09-16T13:42:43.960","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55491","references":[{"url":"https://github.com/bigbluebutton/bigbluebutton/commit/a53f2b92022388bfa4109d3136d1f3a932404b1b","label":"security-advisories@github.com"},{"url":"https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.29","label":"security-advisories@github.com"},{"url":"https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-57p5-c888-74f9","label":"security-advisories@github.com"}],"tags":["nvd"],"epss":0.00165,"epssPercentile":0.06213,"ingestedAt":"2026-09-16T13:56:12.596Z","slug":"CVE-2026-55491","body":"## Overview\n\nBigBlueButton 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":29.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}