Medium [CVE-2026-15943] OIDC IdP update reuses masked client secret after token URL change
This medium-severity Red Hat Linux advisory covers CVE-2026-15943 affecting Red Hat Build of Keycloak.
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Summary
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. The Red Hat Product Security team has assessed the severity of this vulnerability as Moderate, given that it requires high administrative privileges to exploit.
Successful exploitation allows an attacker to rebind and capture an OIDC client secret by modifying identity provider configuration fields. The vulnerability's root cause is the unconditional reuse of masked secrets during configuration updates without verifying if sensitive endpoint fields have changed.
Weakness: CWE-1288. Affected Red Hat products: Red Hat Build of Keycloak.
Red Hat lists Red Hat Data Grid 8; Red Hat JBoss Enterprise Application Platform Expansion Pack; Red Hat Single Sign-On 7 as not affected. Red Hat does not currently list a fixing RHSA for this CVE.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative. Check it before change work.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists. Confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
Mitigation
The source record does not include mitigation steps. That does not mean no fix exists. Read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
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