A flaw was found in the legacy client-initiated account-linking endpoint of Keycloak, a widely used open-source identity and access management solution. The mechanism used to protect the account-linking process from unauthorized requests relies on a hash that can be predicted by a malicious OIDC client. By tricking a user into authenticating, an attacker-controlled client can forge a valid linking URL to connect the victim's account to an attacker's external identity. This results in a full account takeover, allowing the attacker to log in as the victim.

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History

Tue, 18 Aug 2026 21:00:00 +0000

Type Values Removed Values Added
CPEs cpe:/a:redhat:build_keycloak:26.6::el9
References

Tue, 18 Aug 2026 20:45:00 +0000

Type Values Removed Values Added
Description A flaw was found in the legacy client-initiated account-linking endpoint of Keycloak, a widely used open-source identity and access management solution. The mechanism used to protect the account-linking process from unauthorized requests relies on a hash that can be predicted by a malicious OIDC client. By tricking a user into authenticating, an attacker-controlled client can forge a valid linking URL to connect the victim's account to an attacker's external identity. This results in a full account takeover, allowing the attacker to log in as the victim.
Title Keycloak-services: keycloak-services: predictable account-linking hash enables account takeover via malicious oidc client
First Time appeared Redhat
Redhat build Keycloak
Redhat jboss Data Grid
Redhat jbosseapxp
Redhat red Hat Single Sign On
Weaknesses CWE-341
CPEs cpe:/a:redhat:build_keycloak:26.6
cpe:/a:redhat:jboss_data_grid:8
cpe:/a:redhat:jbosseapxp
cpe:/a:redhat:red_hat_single_sign_on:7
Vendors & Products Redhat
Redhat build Keycloak
Redhat jboss Data Grid
Redhat jbosseapxp
Redhat red Hat Single Sign On
References
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-08-18T20:45:34.499Z

Reserved: 2026-07-13T07:12:45.061Z

Link: CVE-2026-15571

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-18T21:16:33.910

Modified: 2026-08-18T21:16:33.910

Link: CVE-2026-15571

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-18T21:15:03Z

Weaknesses