{"id":"CVE-2026-2603","title":"A flaw was found in Keycloak","summary":"A flaw was found in Keycloak. A remote attacker could bypass security controls by sending a valid SAML response from an external Identity Provider (IdP) to the Keycloak SAML endpoint for IdP-initiated broker logins. This allows the attac…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","cwe":["CWE-306","CWE-306"],"vendor":"redhat","product":"build_of_keycloak","affected":["build_of_keycloak >= 26.2, < 26.2.14","build_of_keycloak >= 26.4, < 26.4.10"],"patched":["build_of_keycloak 26.4.10"],"published":"2026-03-18","updated":"2026-08-18","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-2603","references":[{"url":"https://access.redhat.com/errata/RHSA-2026:3925","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:3926","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:3947","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:3948","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/security/cve/CVE-2026-2603","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2440300","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:3925","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:3926","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:3947","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:3948","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/security/cve/CVE-2026-2603","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2440300","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2440300","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2603.json","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}],"tags":["nvd"],"epss":0.00425,"epssPercentile":0.36271,"ingestedAt":"2026-08-18T18:21:28.224Z","slug":"CVE-2026-2603","body":"## Overview\n\nA flaw was found in Keycloak. A remote attacker could bypass security controls by sending a valid SAML response from an external Identity Provider (IdP) to the Keycloak SAML endpoint for IdP-initiated broker logins. This allows the attacker to complete broker logins even when the SAML Identity Provider is disabled, leading to unauthorized authentication.\n\n## Affected\n\n- `build_of_keycloak >= 26.2, < 26.2.14`\n- `build_of_keycloak >= 26.4, < 26.4.10`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `build_of_keycloak 26.4.10`","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}