Public vulnerability disclosure

CVE-2026-97175

Keycloak-services: keycloak-services: unverified idp email auto-linking enables account takeover

publishedCWE-287

A flaw was found in the idp-auto-link authenticator of the keycloak-services component, which handles user identity federation. The issue occurs when Keycloak automatically links an incoming identity from an external provider to an existing local account based on an email address without verifying if the provider has validated that email. This can allow an attacker to take over a victim's account by using a matching unverified email address at a brokered provider.

Technical severity8.8 highCVSS 3.1 · CNA: redhat
Published2026-11-05Source updated 2026-11-09
Collected2026-11-103 attributed sources

Fixes and workarounds

Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. --- CME Mitigation Guidance (2026-11-06) --- Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure. The highest-value action is to require verification of the email verified claim before linking brokered identities to local accounts in the idp-auto-link authenticator: upgrade to Red Hat build of Keycloak 26.4.17 (or the fixed Rhbk/Keycloak Rhel/Keycloak Services builds), which verify the email verified claim before automatically linking an incoming brokered identity to an existing local account, closing federated identity login using unverified matching email address. Until patched, this is a concern on Keycloak deployments configured with the idp-auto-link authenticator in the first-broker-login flow, so audit brokered external identity providers to ensure they enforce email verification, or avoid using external providers that permit arbitrary unverified email addresses matching existing local accounts. As a compensating measure, Enforce multi-factor authentication on target Keycloak accounts to prevent attackers from completing account takeovers even if the federated identity is automatically linked. These controls limit blast radius and contain exploitation, but they do not fix the underlying improper authentication defect — apply the upstream patch to fully remediate. Highest-impact CME: CME-801 Multi-Factor Authentication (MFA) (medium)

Source: CNA: redhat

Affected products and versions

Affected products, source version ranges and reporting authorities
ProductVersionsAuthority
Red Hat build of Keycloak 26.4.17
Red Hat
keycloak-services
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat build of Keycloak 26.4.17
Red Hat
rhbk/keycloak-rhel9
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat build of Keycloak 26.6.8
Red Hat
keycloak-services
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat build of Keycloak 26.6.8
Red Hat
rhbk/keycloak-rhel9
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat Single Sign-On 7
Red Hat
keycloak-services
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / scoreVectorAuthority
3.1 / 8.8
high
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCNA: redhat
3.1 / 8.8
high
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HNVD: [email protected]

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

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