What is the CVSS score of EUVD-2026-50236?

EUVD-2026-50236 has a CVSS 3.1 base score of 7.3 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L. EPSS exploitation probability: 0.2%.

Which versions of Apache Kyuubi are affected by EUVD-2026-50236?

Apache Kyuubi versions 1.8.0-1.11.x contain an unauthenticated Server-Side Request Forgery (SSRF) vulnerability in the Engine UI proxy that enables attackers to forward requests to arbitrary internal…. A patch is available.

How to fix or mitigate EUVD-2026-50236?

Within 24 hours, audit all Kyuubi instances (versions 1.8.0-1.11.x) for external network exposure using vulnerability scanning or asset inventory tools, and immediately restrict network access via firewall rules to permit only trusted, authenticated clients. Within 7 days, disable the Engine UI proxy feature via Kyuubi configuration if operationally unnecessary, and deploy Web Application Firewall rules to block requests targeting proxy endpoints. Within 30 days, monitor Apache Kyuubi security advisories for patch availability and evaluate upgrade feasibility once a patched release is available; until then, maintain network isolation with continuous monitoring for anomalous proxy traffic patterns.

Apache Kyuubi EUVD-2026-50236

| CVE-2026-23904 HIGH

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

2026-07-29

GHSA-qvj4-xxw2-22gf

Apache SSRF Kyuubi

7.3

CVSS 3.1 · Vendor

Severity by source

Vendor (CNA) PRIMARY

7.3 MEDIUM

AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

vuln.today AI

7.2 HIGH

Network-accessible proxy with no authentication per description; scope changes because the server reaches other systems; no integrity or availability impact on the vulnerable host itself.

3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

Primary rating from Vendor (CNA).

CVSS VectorVendor

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

Low

Lifecycle Timeline

Patch available

Jul 29, 2026 - 10:01 EUVD

Analysis Generated

Jul 29, 2026 - 08:19 vuln.today

CVE Published

Jul 29, 2026 - 07:04 oss-security

HIGH

Description PRE-NVD

Disclosed via oss-security. NVD scoring and full description are pending.

AnalysisAI

Server-Side Request Forgery (SSRF) and open-proxy behavior in Apache Kyuubi's Engine UI proxy exposes the Kyuubi server as a request forwarder to arbitrary internal or external hosts. Versions 1.8.0 through 1.11.x accept an attacker-controlled host and port from the HTTP request path and blindly proxy the request to that destination, enabling network pivoting into otherwise unreachable services behind the Kyuubi server. No active exploitation has been confirmed in CISA KEV, and no public exploit code has been identified at time of analysis; however, the unauthenticated network vector and trivial exploitation conditions make this a credible internal reconnaissance risk in exposed deployments.

Technical ContextAI

Apache Kyuubi (org.apache.kyuubi:kyuubi-server) is a distributed, multi-tenant SQL gateway that sits in front of compute engines like Apache Spark and Flink, exposing a JDBC/ODBC/REST interface for lakehouse query workloads. Its Engine UI proxy feature passes a host and port supplied in the REST path directly to an HTTP client without validation or allowlisting, a textbook CWE-918 (Server-Side Request Forgery) pattern. The affected component is the REST frontend's engine.ui.proxy endpoint. The root cause is the absence of any destination restriction - the proxy accepted arbitrary user-supplied targets rather than a pre-configured allowlist. PR #7483 on the Apache Kyuubi GitHub repository represents the upstream fix. The fix in 1.12.0 disables the proxy entirely by default, requiring explicit opt-in and host allowlist configuration via kyuubi.frontend.rest.engine.ui.proxy.enabled and kyuubi.frontend.rest.engine.ui.proxy.hosts.

RemediationAI

Upgrade to Apache Kyuubi 1.12.0, which is the vendor-confirmed fixed release. In 1.12.0, the Engine UI proxy is disabled by default, eliminating the attack surface without any configuration change required. If proxied Engine UI functionality is operationally required after upgrading, it can be re-enabled by setting kyuubi.frontend.rest.engine.ui.proxy.enabled=true and restricting targets to known safe hosts via kyuubi.frontend.rest.engine.ui.proxy.hosts - this allowlist configuration is the key control preventing SSRF. For organizations that cannot immediately upgrade, the most effective compensating control is to restrict network access to the Kyuubi REST frontend to trusted clients only via firewall or network segmentation, preventing untrusted requesters from reaching the proxy endpoint; note this does not fix the underlying flaw and any trusted-but-compromised client retains the ability to abuse the proxy. Additionally, blocking outbound HTTP from the Kyuubi server to RFC-1918 address ranges and cloud metadata service IPs (169.254.169.254, fd00:ec2::254) limits the SSRF blast radius if patching is delayed. The advisory is available at the Apache Kyuubi project site https://kyuubi.apache.org.