{"id":"CVE-2026-15571","aliases":["BIT-keycloak-2026-15571","EUVD-2026-61238","GHSA-m639-f4cw-m3hm"],"status":"published","title":"Keycloak-services: keycloak-services: predictable account-linking hash enables account takeover via malicious oidc client","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.","severity":{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0043,"percentile":0.3766,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-341"],"published":"2026-08-18T20:40:17Z","modified":"2026-08-26T11:15:06Z","fixes":[{"ecosystem":"Bitnami","package":"keycloak","fixed_in":["26.7.2"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Bitnami","package":"keycloak","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"26.7.2"}]}]}],"products":[{"vendor":"red hat","product":"red hat build of keycloak 26.6"},{"vendor":"red hat","product":"red hat build of keycloak 26.6.6"},{"vendor":"red hat","product":"red hat data grid 8"},{"vendor":"red hat","product":"red hat jboss enterprise application platform expansion pack"},{"vendor":"red hat","product":"red hat single sign-on 7"}],"references":[{"url":"https://access.redhat.com/errata/RHSA-2026:56523","tags":["vendor-advisory","x_refsource_REDHAT","web"]},{"url":"https://access.redhat.com/errata/RHSA-2026:56524","tags":["vendor-advisory","x_refsource_REDHAT","web"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-15571","tags":["vdb-entry","x_refsource_REDHAT","web"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2499591","tags":["issue-tracking","x_refsource_REDHAT","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-15571","tags":["web"]},{"url":"https://github.com/advisories/GHSA-m639-f4cw-m3hm"}],"sources":{"cve":[{"id":"CVE-2026-15571","title":"Keycloak-services: keycloak-services: predictable account-linking hash enables account takeover via malicious oidc client","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.","status":"published","published":"2026-08-18T20:40:17.77Z","modified":"2026-08-20T14:07:09.247Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-341"],"updated_at":"2026-11-02T13:47:51.033687Z"}],"euvd":[{"id":"EUVD-2026-61238","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.","status":"published","published":"2026-08-18T20:40:17Z","modified":"2026-08-20T14:07:09Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T18:01:40.451894Z"}],"ghsa":[{"id":"GHSA-m639-f4cw-m3hm","title":"A flaw was found in the legacy client-initiated account-linking endpoint of Keycloak, a widely...","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.","status":"published","published":"2026-08-18T21:31:53Z","modified":"2026-08-18T21:31:59Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-341"],"updated_at":"2026-11-02T15:10:37.733287Z"}],"nvd":[{"id":"CVE-2026-15571","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.","status":"published","published":"2026-08-18T21:16:33.91Z","modified":"2026-08-20T15:17:28.117Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-341"],"updated_at":"2026-11-02T14:12:38.976695Z"}],"osv":[{"id":"BIT-keycloak-2026-15571","title":"Flaw in the legacy client-initiated account-linking endpoint of Keycloak","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.","status":"published","published":"2026-08-25T10:46:44.542Z","modified":"2026-08-26T11:15:06.505464719Z","updated_at":"2026-11-02T15:28:32.162822Z"}]}}