CVE-2026-15943: Keycloak-services: keycloak-services: oidc idp update reuses masked client secret after token url change

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-17 · updated 2026-08-09
Weakness: CWE-1288

Description

A flaw was found in the Keycloak keycloak-services component, which handles the management of identity providers. The issue occurs when a delegated administrator updates an OIDC identity provider using a masked client secret sentinel value. Due to improper validation, Keycloak reuses the existing real secret even if security-sensitive fields like the token URL have been changed, allowing an attacker to redirect and capture the secret.

Affected products

Red Hat build of Keycloak 26.4: all versions

References

https://access.redhat.com/security/cve/CVE-2026-15943
https://bugzilla.redhat.com/show_bug.cgi?id=2501270

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