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

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

- **Severity:** Medium 4.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N`)
- **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:** Yes
- **Published:** 28 May 2026
- **Updated:** 29 May 2026
- **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, MINI-p5qp-rr9m-x3pp, MINI-pwj2-c2mx-cc92, MINI-rff2-pq64-73vc

## 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 (Improper Neutralization of Input During Web Page Generation)

## 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 | Ecosystem | 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: 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.

## Is CVE-2026-42401 being exploited?

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

## Other vulnerabilities in Elastic Kibana

- [CVE-2019-7609](https://insights.sbomify.com/CVE-2019-7609/): Kibana Arbitrary Code Execution (critical 9.8, exploited in the wild)
- [CVE-2025-25015](https://insights.sbomify.com/CVE-2025-25015/): Kibana arbitrary code execution via prototype pollution (critical 9.9)
- [CVE-2024-37288](https://insights.sbomify.com/CVE-2024-37288/): Deserialization in Kibana (critical 9.9)
- [CVE-2023-31415](https://insights.sbomify.com/CVE-2023-31415/): Code injection in Kibana (critical 9.9)
- [CVE-2018-17245](https://insights.sbomify.com/CVE-2018-17245/): Information disclosure in Kibana (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42401 and fix it if it is affected.

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

Affected packages and fixed versions:
- kibana (Bitnami): affected from 8.0.0; fixed in 8.19.16, 9.3.5
- elk (Bitnami): affected from 8.0.0; fixed in 8.19.16, 9.3.5

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-42401/ (Markdown: https://insights.sbomify.com/CVE-2026-42401/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42401
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42401
- OSV: https://osv.dev/vulnerability/CVE-2026-42401

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42401/
Summaries are generated and may contain mistakes; the official description above is the record.