🛡️ CVE-2026-9086 — build-of-keycloak
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
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| build-of-keycloak | 26.6 | 26.6.4 |
References
Similar Threats
- High CVE-2026-15572
- High CVE-2026-15573
- Medium CVE-2026-15943
- Medium CVE-2026-15945
- Medium CVE-2026-12388
More CVE 2026 advisories
Browse all of CVE 2026 in the advisory index.
Site Security Check
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