What is CVE-2026-42401?

CVE-2026-42401 is a medium-severity vulnerability in Elastic Kibana, classified under Cross-site Scripting. CVSS score: 4.1/10. Published 2026-05-28.

How severe is CVE-2026-42401?

Medium severity. CVSS v3 base score is 4.1 out of 10.

XSS in Elastic Kibana

CVE-2026-42401

Improper Neutralization of Input During Web Page Generation (CWE-79) in Kibana can lead to stored HTML injection. A user with write access to an Elasticsearch index could persist crafted markup which, when subsequently rendered through an…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.000 (6.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N.

Affected products

Elastic Kibana — versions 9.0.0, 8.0.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security@elastic.co (Vendor Advisory)

Frequently asked questions

What is CVE-2026-42401?: CVE-2026-42401 is a medium-severity vulnerability in Elastic Kibana, classified under Cross-site Scripting. CVSS score: 4.1/10. Published 2026-05-28.
How severe is CVE-2026-42401?: Medium severity. CVSS v3 base score is 4.1 out of 10.