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.
Affected products
redhat: build of keycloak
References4
- access.redhat.com/errata/RHSA-2026:19596 Vendor Advisory
- access.redhat.com/errata/RHSA-2026:19597 Vendor Advisory
- access.redhat.com/security/cve/CVE-2026-7571 Vendor Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2464263 Vendor Advisory
Metrics
- CVSS 3.1
-
7.1
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N - EPSS — exploit probability
- 0% percentile: 36 · as of 14 November 2026
- CWE
- CWE-472
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.