CVE-2026-18211
A flaw was found in the secure-client-uris client policy executor within Keycloak core services.
Does this matter?
Lower severity and a low EPSS score (0.31%). Track it; it rarely justifies an emergency change on its own.
Description
A flaw was found in the secure-client-uris client policy executor within Keycloak core services. This component is responsible for enforcing security requirements on client configurations, such as requiring encrypted connections for redirect URIs. Due to an improper check that only looks at the start of a web address rather than properly verifying the host, an attacker can bypass these security restrictions by using a specially crafted domain name. This could allow an attacker to intercept sensitive authentication codes over unencrypted connections.
- CVSS 3.1
- 5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
- EPSS
- 0.31% probability · 23th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-20
- Affected
- redhat/build of keycloak
- Source
- secalert@redhat.com
EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://access.redhat.com/security/cve/CVE-2026-18211Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2508306Issue Tracking, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.