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Fencer Vulns
high 7.1

CVE-2025-55200 json

BigBlueButton vulnerable to Stored XSS via name of user at Shared Notes

published 2025-10-09 13 mo ago modified 2026-10-19 20 d ago also EUVD-2025-33584

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

BigBlueButton is an open-source virtual classroom. In versions prior to 3.0.13, the "Shared Notes" feature contains a Stored Cross-Site Scripting (XSS) vulnerability with the input location being the "Username" field and the output location on the "Shared Notes" page, when a user with a malicious username is editing content. This vulnerability allows a low-privileged user to execute arbitrary JavaScript in the context of higher-privileged users (e.g., Admins) who open the Shared Notes page. Version 3.0.13 fixes the issue.

Patch / fix

  • bigbluebutton bigbluebutton 3.0.13

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
13 mo ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected products

  • bigbluebutton bigbluebutton

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.