Keycloak: cross-session email verification proof not bound to upstream identity in first-broker-login (Red Hat Red Hat build of Keycloak 26.4)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.31 % · percentile 24 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- redhat
- NVD status
- Modified
Description
A flaw was found in Keycloak. The cross-session verification proof is keyed only by (local userId, idpAlias) and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account.
Weaknesses (CWE)
- CWE-639 — Authorization Bypass Through User-Controlled Key
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.4 | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N | redhat |
| CVSS 3.1 | MEDIUM 6.4 | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N | NVD · secalert@redhat.com (Secondary) |
| CVSS 3.1 | HIGH 8.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N | NVD · nvd@nist.gov (Primary) |
Advisories
- GHSA-m6qj-3mpp-57v8 — Keycloak: Insufficient verification proof scoping enables identity provider account linking attack and account compromise
European references
- ENISA EUVD · EUVD-2026-31134
- GCVE · GCVE-0-2026-9087
Affected configurations (NVD CPE)
cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*
Affected products
| Product | Versions |
|---|---|
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4.13-1 < * |
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4-19 < * |
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4-19 < * |
| Red Hat · Red Hat build of Keycloak 26.4.13 | |
| Red Hat · Red Hat build of Keycloak 26.6 | unaffected 26.6.3-3 < * |
| Red Hat · Red Hat build of Keycloak 26.6 | unaffected 26.6-6 < * |
| Red Hat · Red Hat build of Keycloak 26.6 | unaffected 26.6-6 < * |
| Red Hat · Red Hat build of Keycloak 26.6.3 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |