Keycloak: keycloak: cross-site scripting (xss) via case-insensitive uri validation bypass (Red Hat Red Hat build of Keycloak 26.4)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.78 % · percentile 56 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- redhat
- NVD status
- Analyzed
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.
Weaknesses (CWE)
- CWE-79 — Improper Neutralization of Input During Web Page Generation
References
- https://access.redhat.com/errata/RHSA-2026:30049
- https://access.redhat.com/errata/RHSA-2026:30050
- https://access.redhat.com/errata/RHSA-2026:30083
- https://access.redhat.com/errata/RHSA-2026:30084
- https://access.redhat.com/security/cve/CVE-2026-9086
- https://bugzilla.redhat.com/show_bug.cgi?id=2480170
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-9086.json
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N | redhat |
| CVSS 3.1 | HIGH 7.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N | redhat-SADP |
| CVSS 3.1 | HIGH 7.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N | NVD · secalert@redhat.com (Secondary) |
| CVSS 3.1 | HIGH 7.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N | NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary) |
European references
- ENISA EUVD · EUVD-2026-39473
- GCVE · GCVE-0-2026-9086
CERT-FR advisories
- CERTFR-2026-AVI-0815 — Multiples vulnérabilités dans KeyCloak · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:*≥ 26.4 < 26.4.13cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:*≥ 26.6 < 26.6.4
Affected products
| Product | Versions |
|---|---|
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4.13-1 < * |
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4-19 < * |
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4-19 < * |
| Red Hat · Red Hat build of Keycloak 26.4.13 | |
| Red Hat · Red Hat build of Keycloak 26.6 | unaffected 26.6.4-2 < * |
| Red Hat · Red Hat build of Keycloak 26.6 | unaffected 26.6-8 < * |
| Red Hat · Red Hat build of Keycloak 26.6 | unaffected 26.6-8 < * |
| Red Hat · Red Hat build of Keycloak 26.6.4 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |