🛡️ CVE-2026-9086 — build-of-keycloak

🟠 CVSS 7.3 — High ✅ No Known Exploit CWE-79 NVD
7.3
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

A flaw was found in Keycloak. A remote attacker with administrative privileges, specifically those with manage-client permission or access to client registration endpoints, could bypass client Uniform Resource Identifier (URI) validation. This is achieved by registering a malicious client with a specially crafted redirect URI using a case-insensitive javascript: or data: scheme. This Cross-Site Scripting (XSS) vulnerability allows for arbitrary code execution in the Keycloak origin when a victim clicks the crafted link, such as in the logout flow or the Admin Console.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability none.

Weakness class

CVE-2026-9086 is classified as CWE-79: Cross-site Scripting (XSS). User-supplied data is written into a page without escaping, so attacker script runs in the browser of anyone who views it.

Affected software

CVE-2026-9086 is recorded against 1 package.

  • build-of-keycloak (from 26.6 up to 26.6.4)

Timeline and source

Published on 25 June 2026 and last revised on 15 July 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
bugzilla.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
bugzilla.redhat.com
security.access.redhat.com

Details

Severity HIGH
CVSS Score 7.3
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
CWE CWE-79
Public Exploit ✅ No
Source NVD
Published 2026-06-25
Updated 2026-08-11
Modified 2026-07-15
Fix URL N/A

Affected Packages

Software From version Fixed in
build-of-keycloak 26.6 26.6.4

References

Similar Threats

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