CVE-2026-9705
Description
A flaw was found in Keycloak's client registration service. A remote attacker, possessing a previously issued Registration Access Token (RAT), could exploit this vulnerability to re-enable a client that an administrator had explicitly disabled. This bypasses security controls, allowing the attacker to reset the client's secret and potentially regain privileged API access. The primary impact includes unauthorized information disclosure and potential integrity compromise.
Statement
A Moderate flaw was found in Keycloak where a disabled client can be re-enabled by an attacker who retains a Registration Access Token (RAT) from a prior legitimate client registration. This allows the attacker to bypass the administrator's explicit intent to disable the client, reset its secret, and restore OAuth client_credentials capability, potentially leading to unauthorized access to resources.
Mitigation
To mitigate this issue, restrict network access to the Keycloak Dynamic Client Registration endpoint. Configure network firewalls to allow connections only from trusted hosts or networks that legitimately require access to this functionality. This limits the exposure of the vulnerable endpoint to unauthorized access attempts.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | 6.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
Acknowledgements
Red Hat would like to thank Qiulin Deng for reporting this issue.
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