XSS in Bludit

CVE-2026-4420

Bludit is vulnerable to Stored Cross-Site Scripting (XSS) in its page creating functionality. An authenticated attacker with page creation privileges (such as Author, Editor, or Administrator) can embed a malicious JavaScript payload in the tags field of a newly created article. This payload will be executed when a victim visits the URL of the uploaded resource. The uploaded resource itself is accessible without authentication. Critically, this vulnerability could be used to automatically create a new site administrator if the victim has enough privileges.  The vendor was notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Only versions 3.17.2 and 3.18.0 were tested and confirmed as vulnerable, other versions were not tested and might also be vulnerable.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (5.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

Affected products

  • Bludit — versions 3.17.2, 3.18.0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-4420?
CVE-2026-4420 is a medium-severity vulnerability in Bludit, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-04-07.
How severe is CVE-2026-4420?
Medium severity. CVSS v3 base score is 5.4 out of 10.