CVE-2026-18573: Keycloak-services: keycloak-services: client access-type policy condition bypass during client update
Vulnerability summary
CVE-2026-18573 is a medium (CVSS 6.5) Missing Authorization vulnerability in redhat build_of_keycloak. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 40.4% of scored vulnerabilities.
Timeline
- 02-08-2026PublishedVulnerability first disclosed.
- 16-09-2026Last modifiedVulnerability information updated.
Description
A flaw was found in the keycloak-services component of Keycloak, which is used for managing authentication and authorization flows. The issue occurs when a realm administrator configures client policies to enforce specific authentication requirements on confidential clients. Due to improper evaluation of the client state during an update operation, an attacker with client management permissions can bypass these security policies by first creating a public client and then updating it to a confidential client with weaker authentication. This can result in the persistence of clients that do not comply with the intended security hardening of the realm.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
EPSS trend
Probability
0.48%
Chance of exploitation in the next 30 days
Percentile
40%
Versus all other CVEs
30-day change
Increase +0.21 pp
From 0.27% on 22-09-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Redhat1 product
1 vendor · 1 product