CVE-2026-4630: Keycloak: keycloak: unauthorized resource access and data modification via insecure direct object reference

Severity: medium (CVSS 6.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-19 · updated 2026-10-26
Weakness: CWE-639

Description

A flaw was found in Keycloak. An authenticated client could exploit an Insecure Direct Object Reference (IDOR) vulnerability in the Authorization Services Protection API endpoint. By knowing or obtaining a resource's unique identifier (UUID) belonging to another Resource Server within the same realm, the client could bypass authorization checks. This allows the client to perform unauthorized GET, PUT, and DELETE operations on resources, leading to information disclosure and potential unauthorized modification or deletion of data.

Affected products

Red Hat build of Keycloak 26.4: from 26.4 before 26.4.12 — fixed in 26.4.12

How to fix

Upgrade to a fixed version: Red Hat build of Keycloak 26.4 26.4.12. Check the vendor advisory for mitigations.

References

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