{"id":"CVE-2026-9086","aliases":["GHSA-v3f7-2p4r-mwfw"],"title":"Keycloak vulnerable to cross-site scripting (xss) via case-insensitive uri validation bypass","summary":"Keycloak vulnerable to cross-site scripting (xss) via case-insensitive uri validation bypass","severity":"high","cvss":7.3,"cwe":["CWE-79"],"vendor":"keycloak","product":"org.keycloak:keycloak-services","ecosystem":"maven","affected":["org.keycloak:keycloak-services < 26.6.4"],"patched":["org.keycloak:keycloak-services 26.6.4"],"published":"2026-10-29","updated":"2026-10-29","sourceUpdated":"2026-10-29T16:39:04Z","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-v3f7-2p4r-mwfw","references":[{"url":"https://github.com/keycloak/keycloak/security/advisories/GHSA-v3f7-2p4r-mwfw"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9086"},{"url":"https://access.redhat.com/errata/RHSA-2026:30049"},{"url":"https://access.redhat.com/errata/RHSA-2026:30050"},{"url":"https://access.redhat.com/errata/RHSA-2026:30083"},{"url":"https://access.redhat.com/errata/RHSA-2026:30084"},{"url":"https://access.redhat.com/security/cve/CVE-2026-9086"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2480170"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-9086.json"},{"url":"https://github.com/advisories/GHSA-v3f7-2p4r-mwfw"}],"tags":["ghsa","maven","exploit-available"],"epss":0.00781,"epssPercentile":0.55861,"exploits":{"github":1,"githubRepos":["https://github.com/Saku0512/CVE-2026-9086-poc"],"checkedAt":"2026-10-29T17:40:15.661Z"},"exploitAvailable":true,"ingestedAt":"2026-10-29T17:39:38.162Z","slug":"CVE-2026-9086","body":"## Overview\n\n### Description\nA 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.\n\n## Affected packages\n\n- `org.keycloak:keycloak-services < 26.6.4`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `org.keycloak:keycloak-services 26.6.4`","depth":"midnight","depthScore":52,"depthScoreParts":{"impact":40.2,"likelihood":0.2,"exploitation":12,"ransomware":0},"changes":[]}