What is CVE-2020-25902?

CVE-2020-25902 is a medium-severity vulnerability in Blackboard Collaborate Ultra, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-03-02.

How severe is CVE-2020-25902?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Blackboard Collaborate Ultra

CVE-2020-25902

Blackboard Collaborate Ultra 20.02 is affected by a cross-site scripting (XSS) vulnerability. The XSS payload will execute on the class room, which leads to stealing cookies from users who join the class. NOTE: Third-parties dispute the validity of this entry as a possible false positive during research

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-03-02 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (51.1th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: +0.000

Affected products

Blackboard Collaborate Ultra — versions 20.02

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

www.blackboard.com/teaching-learning/collaboration-web-conferencing/blackboard-… (Product, Vendor Advisory)
github.com/Lawyer-1/Turki/blob/main/CVE-2020-25902.md (Broken Link)

Frequently asked questions

What is CVE-2020-25902?: CVE-2020-25902 is a medium-severity vulnerability in Blackboard Collaborate Ultra, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-03-02.
How severe is CVE-2020-25902?: Medium severity. CVSS v3 base score is 6.1 out of 10.