{"id":"CVE-2026-55491","state":"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.","publishedAt":"2026-08-20T21:35:42.546Z","updatedAt":"2026-08-21T15:50:11.735Z","severity":{"score":5.4,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["bigbluebutton bigbluebutton"],"affected":[{"vendor":"bigbluebutton","product":"bigbluebutton","versions":[{"version":"< 3.0.29","status":"affected"}]}],"references":["https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-57p5-c888-74f9","https://github.com/bigbluebutton/bigbluebutton/commit/a53f2b92022388bfa4109d3136d1f3a932404b1b","https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.29"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55491.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55491","state":"PUBLISHED","datePublished":"2026-08-20T21:35:42.546Z","dateUpdated":"2026-08-21T15:50:11.735Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T22:28:27.062Z"},"containers":{"cna":{"title":"BigBlueButton: Stored XSS in Screenshare Recording Playback via Unescaped Meeting Name","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"bigbluebutton","product":"bigbluebutton","versions":[{"version":"< 3.0.29","status":"affected"}]}],"references":[{"url":"https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-57p5-c888-74f9","name":"https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-57p5-c888-74f9","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/bigbluebutton/bigbluebutton/commit/a53f2b92022388bfa4109d3136d1f3a932404b1b","name":"https://github.com/bigbluebutton/bigbluebutton/commit/a53f2b92022388bfa4109d3136d1f3a932404b1b","tags":["x_refsource_MISC"]},{"url":"https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.29","name":"https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.29","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.4,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-20T21:35:42.546Z"},"source":{"advisory":"GHSA-57p5-c888-74f9","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-21T15:49:35.408716Z","id":"CVE-2026-55491","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-21T15:50:11.735Z"}}]}}}