CVE-2026-1529: Org.keycloak.services.resources.organizations: keycloak: unauthorized organization registration via improper invitation token validation

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-09 · updated 2026-07-15
Weakness: CWE-347

Description

A flaw was found in Keycloak. An attacker can exploit this vulnerability by modifying the organization ID and target email within a legitimate invitation token's JSON Web Token (JWT) payload. This lack of cryptographic signature verification allows the attacker to successfully self-register into an unauthorized organization, leading to unauthorized access.

Affected products

Red Hat build of Keycloak 26.4: all versions — fixed in 26.2-15, 26.2.13-1, 26.4-10, 26.4-11, 26.4.9-1

How to fix

Upgrade to a fixed version: Red Hat build of Keycloak 26.4 26.2-15, 26.2.13-1, 26.4-10, 26.4-11. Check the vendor advisory for mitigations.

References

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