Affects Keycloak, a widely used IAM platform; enables auth bypass in SAML broker flow.
CVE-2026-2603
Keycloak SAML IdP-broker bypass allows login with a valid SAML response.
Is CVE-2026-2603 being exploited?
Not confirmed. CVE-2026-2603 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.43% probability of exploitation in the next 30 days.
How severe is CVE-2026-2603?
CVE-2026-2603 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-2603?
Yes. A fix has been recorded for CVE-2026-2603. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-2603 affect?
CVE-2026-2603 affects Keycloak. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-2603?
Patch Keycloak; verify broker configs and SAML settings.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attacker can authenticate as any user via IdP-broker login using a valid SAML response, bypassing IdP checks.
Patch when possible