CVE-2026-42401 Improper Neutralization of Input During Web Page Generation in Kibana Leading to Stored HTML Injection

Medium 4.1 Published 28 May 2026 Updated 29 May 2026

An attacker with write access can inject malicious HTML into Kibana views, leading to script execution in other users' browsers.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: Available

What is CVE-2026-42401?

CVE-2026-42401 is a medium-severity cross-site scripting vulnerability in Elastic Kibana, published on 28 May 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

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 affected Kibana view by another user, was not sufficiently sanitized. Successful exploitation could result in unauthorized UI manipulation and outbound network requests issued from the viewing user's browser session.

Weakness: CWE-79

Which versions are affected by CVE-2026-42401?

2 open source packages ship an affected version, including kibana and elk. It affects 1 product.

Package	Affected	Fixed in
`kibana` Bitnami	From `8.0.0`	`8.19.16, 9.3.5`
`elk` Bitnami	From `8.0.0`	`8.19.16, 9.3.5`

Products include Elastic Kibana.

How do I fix CVE-2026-42401?

Upgrade kibana to a fixed version for your release line: 8.19.16 or 9.3.5.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-42401 being exploited?

There is no known exploitation of CVE-2026-42401 in the wild and no public exploit code.

All Elastic Kibana vulnerabilities

Sources

Also known as BIT-elk-2026-42401, BIT-kibana-2026-42401, GHSA-7r23-c4px-q9xc, MINI-4q8h-f3qq-m2pj, MINI-c66h-f4p3-x4qh, MINI-fm59-3q8h-5wr2 and 3 more.