7.3

CVE-2026-9086

Keycloak: keycloak: cross-site scripting (xss) via case-insensitive uri validation bypass

Cross-site scripting (xss) via case-insensitive uri validation bypass

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.
Mögliche Gegenmaßnahme
Keycloak Server: Install latest version
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Redhat ≫ Build Of Keycloak Version >= 26.4 < 26.4.13
Redhat ≫ Build Of Keycloak Version >= 26.6 < 26.6.4
VulnDex Vulnerability Enrichment
Diese Information steht angemeldeten Benutzern zur Verfügung. Login Login
Weitere Schwachstelleninformationen
SystemKeycloak
≫
Produkt Keycloak Server
Version < 26.6.4
Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.42% 0.337
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
secalert@redhat.com 7.3 2.1 5.2
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
0b0ca135-0b70-47e7-9f44-1890c2a1c46c 7.3 2.1 5.2
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

https://access.redhat.com/security/cve/CVE-2026-9086
Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2480170
Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:30083
Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:30084
Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:30049
Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:30050
Third Party Advisory
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-9086.json
Third Party Advisory
https://github.com/keycloak/keycloak/security/advisories/GHSA-v3f7-2p4r-mwfw
Third Party Advisory