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.
{
"cwe_ids": [
"CWE-79"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55491.json"
}{
"source": [
"AFFECTED_FIELD",
"REFERENCES"
],
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "3.0.29"
}
]
}