CVE-2026-15943 Keycloak-services: keycloak-services: oidc idp update reuses masked client secret after token url change
Attackers can capture OIDC client secrets by changing token URLs while reusing masked secrets, compromising identity provider security.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-15943?
CVE-2026-15943 is a medium-severity vulnerability in Redhat Build of Keycloak, published on 17 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official 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.
Weakness: CWE-1288
Which versions are affected by CVE-2026-15943?
It affects 1 product.
Products include Redhat Build of Keycloak.
How do I fix CVE-2026-15943?
No fix has been published for CVE-2026-15943 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-15943 being exploited?
There is no known exploitation of CVE-2026-15943 in the wild and no public exploit code.
Other vulnerabilities in Redhat Build of Keycloak
- CVE-2026-15572 Keycloak-services: keycloak-services: dcr protocol mapper type-swap policy bypass allows privilege escalation
- CVE-2026-3047 Keycloak SAML Broken has Authentication Bypass by Primary Weakness
- CVE-2026-15573 Keycloak-services: keycloak-services: authorization bypass via unnormalized uri matching in pathmatcher
- CVE-2026-16102 Keycloak-services: keycloak-services: default dcr policy allows role forgery via user property mappers
- CVE-2026-1609 Org.keycloak/keycloak-quarkus-server: keycloak: unauthorized access via jwt authorization grant with disabled users
Sources
Also known as GHSA-rpfh-mgxm-c6hc.