CVE-2026-7571
Keycloak: keycloak: access token disclosure and implicit flow bypass via forged client data
- State
- Published
- Severity
- 7.1 High
- Published
- May 19, 2026
- Updated
- May 20, 2026
- Reserved
- Apr 30, 2026
Description
A flaw was found in Keycloak. A low-privilege user, with knowledge of user credentials and client ID, can bypass a security control intended to disable the implicit flow in OpenID Connect (OIDC) clients. By manipulating client data during a session restart, an attacker can obtain an access token that should not be available. This vulnerability can also lead to the exposure of these access tokens in server logs, proxy logs, and HTTP Referrer headers, resulting in sensitive information disclosure.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.1 High | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N | redhat |
Weaknesses
- CWE-472 External Control of Assumed-Immutable Web Parameter
Affected Products
| Product | Versions |
|---|---|
Red Hat build of Keycloak 26.4Red Hat |
|
Red Hat build of Keycloak 26.4Red Hat |
|
Red Hat build of Keycloak 26.4Red Hat |
|
Red Hat build of Keycloak 26.4.12Red Hat |
References
- RHSA-2026:19596vendor-advisory
- RHSA-2026:19597vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-7571vdb-entry
- RHBZ#2464263issue-tracking
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