{"id":"CVE-2026-16093","title":"Keycloak provides a mechanism called Client Policies to enforce security requirements on clients, such as requiring them to use signed JWTs for authentication","summary":"Keycloak provides a mechanism called Client Policies to enforce security requirements on clients, such as requiring them to use signed JWTs for authentication. A flaw was discovered where this enforcement can be bypassed. An attacker wit…","severity":"medium","cvss":5.4,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","cwe":["CWE-807"],"vendor":"redhat","product":"build_of_keycloak","affected":["build_of_keycloak","data_grid = 8.0","jboss_enterprise_application_platform_expansion_pack","single_sign-on = 7.0"],"patched":["build_of_keycloak 26.6.7"],"published":"2026-07-17","updated":"2026-09-16","sourceUpdated":"2026-09-16T19:17:07.373","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-16093","references":[{"url":"https://access.redhat.com/errata/RHSA-2026:68277","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:68278","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/security/cve/CVE-2026-16093","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2501729","label":"secalert@redhat.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-16093.json"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-16093"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-16093"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00393,"epssPercentile":0.3325,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-07-21T01:45:36.335145Z"},"ingestedAt":"2026-08-09T15:33:36.435Z","slug":"CVE-2026-16093","body":"## Overview\n\nKeycloak provides a mechanism called Client Policies to enforce security requirements on clients, such as requiring them to use signed JWTs for authentication. A flaw was discovered where this enforcement can be bypassed. An attacker with valid client credentials can provide a fake, unsigned assertion header that tricks the system into thinking the policy requirements have been met. This allows the attacker to authenticate using simpler methods like a client secret even when the administrator has mandated more secure, signed assertions.\n\n## Affected\n\n- `build_of_keycloak`\n- `data_grid = 8.0`\n- `jboss_enterprise_application_platform_expansion_pack`\n- `single_sign-on = 7.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:68278** · Red Hat · fixed in: Red Hat build of Keycloak 26.6.7 · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:68278)\n- **Red Hat VEX** · Moderate · affected: Red Hat Data Grid 8, Red Hat JBoss Enterprise Application Platform Expansion Pack, Red Hat Single Sign-On 7 · no fix planned: Red Hat Data Grid 8, Red Hat JBoss Enterprise Application Platform Expansion Pack, Red Hat Single Sign-On 7 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-16093.json)\n- **RHSA-2026:68277** · Red Hat · fixed in: Red Hat build of Keycloak 26.6 · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:68277)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":29.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}