Authenticated privilege escalation via group-path prefix collision
Published Jul 31, 2026 · Updated Jul 31, 2026
Incorrect authorization in Red Hat build of Keycloak allows remote authenticated users to gain unauthorized realm permissions. GroupPolicyProvider evaluates extendChildren membership with a raw string prefix comparison that ignores group-path delimiters, so a similarly named sibling satisfies the policy. Exploitation requires low-privileged authentication, an active extendChildren policy, and a prefix-colliding sibling group; success grants protected administrative or resource permissions.
Summary
What happened
Incorrect authorization in Red Hat build of Keycloak allows remote authenticated users to gain unauthorized realm permissions. GroupPolicyProvider evaluates extendChildren membership with a raw string prefix comparison that ignores group-path delimiters, so a similarly named sibling satisfies the policy. Exploitation requires low-privileged authentication, an active extendChildren policy, and a prefix-colliding sibling group; success grants protected administrative or resource permissions.
The record
- CVE
- CVE-2026-18203
- Published
- Jul 31, 2026
- Updated
- Jul 31, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat build of Keycloak
- Classifications
- CWE-863, T1068
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 31, 2026CVE publishedPublication date reported by the CVE source.
- Jul 31, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo