# CVE-2026-23904: Apache Kyuubi: Unrestricted access via Kyuubi engine-ui proxy

> Remote attackers can exploit the Kyuubi Engine UI proxy to send HTTP requests to arbitrary hosts, enabling Server-Side Request Forgery attacks.

- **Severity:** High 7.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Jul 2026
- **Updated:** 29 Jul 2026
- **Also known as:** GHSA-qvj4-xxw2-22gf

## What is CVE-2026-23904?

CVE-2026-23904 is a high-severity server-side request forgery vulnerability in Apache Kyuubi, published on 29 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Kyuubi Engine UI proxy accepts a host and port from the request path and proxies HTTP requests to that destination. A remote requester with network access to the proxy can cause the Kyuubi server to send HTTP requests to arbitrary reachable hosts, resulting in SSRF or open-proxy behavior.

This issue affects Apache Kyuubi: from 1.8.0 before 1.12.0.

Users are recommended to upgrade to version 1.12.0, which disables the proxy by default. To restore proxied Engine UI, set kyuubi.frontend.rest.engine.ui.proxy.enabled=true and configure allowed target hosts with kyuubi.frontend.rest.engine.ui.proxy.hosts.

Weakness: CWE-923 (Improper Restriction of Communication Channel to Intended Endpoints)

## Which versions are affected by CVE-2026-23904?

It affects 1 product.


Products: Apache Kyuubi.

## How do I fix CVE-2026-23904?

No fix has been published for CVE-2026-23904 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-23904 being exploited?

There is no known exploitation of CVE-2026-23904 in the wild and no public exploit code.

## Other vulnerabilities in Apache Kyuubi

- [CVE-2026-52680](https://insights.sbomify.com/CVE-2026-52680/): Apache Kyuubi: REST batch multipart upload path traversal allows controlled file write (critical 9.8)
- [CVE-2025-66518](https://insights.sbomify.com/CVE-2025-66518/): Apache Kyuubi: Unauthorized directory access due to missing path normalization (high 8.8)
- [CVE-2026-62391](https://insights.sbomify.com/CVE-2026-62391/): Apache Kyuubi: kyuubi.session.local.dir.allow.list bypass via unprefixed Spark file-conf aliases (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23904 and fix it if it is affected.

What it is: CVE-2026-23904 is a high-severity server-side request forgery vulnerability in Apache Kyuubi, published on 29 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-23904 in the wild and no public exploit code.

Affected product: Apache Kyuubi. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-23904/ (Markdown: https://insights.sbomify.com/CVE-2026-23904/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23904
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23904
- OSV: https://osv.dev/vulnerability/CVE-2026-23904

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23904/
Summaries are generated and may contain mistakes; the official description above is the record.