GHSA-v3f7-2p4r-mwfw
Keycloak vulnerable to cross-site scripting (xss) via case-insensitive uri validation bypass
At a glance
- Published
- Updated
- CVE
- CVE-2026-9086
- Aliases
- BIT-keycloak-2026-9086
- CVSS_V3
- CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
Description
### 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.
Affected packages
| Package | Versions |
|---|---|
| Maven · org.keycloak:keycloak-services | introduced 0, fixed 26.6.4 |
References
- https://github.com/keycloak/keycloak/security/advisories/GHSA-v3f7-2p4r-mwfw WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-9086 ADVISORY
- https://access.redhat.com/errata/RHSA-2026:30049 WEB
- https://access.redhat.com/errata/RHSA-2026:30050 WEB
- https://access.redhat.com/errata/RHSA-2026:30083 WEB
- https://access.redhat.com/errata/RHSA-2026:30084 WEB
- https://access.redhat.com/security/cve/CVE-2026-9086 WEB
- https://bugzilla.redhat.com/show_bug.cgi?id=2480170 WEB
- https://github.com/keycloak/keycloak PACKAGE
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-9086.json WEB
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |