{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-9087", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-05-20T14:53:18.352Z", "datePublished": "2026-05-20T16:13:03.022Z", "dateUpdated": "2026-05-20T16:13:03.022Z"}, "containers": {"cna": {"title": "Keycloak: cross-session email verification proof not bound to upstream identity in first-broker-login", "metrics": [{"other": {"content": {"value": "Moderate", "namespace": "https://access.redhat.com/security/updates/classification/"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N", "version": "3.1"}, "format": "CVSS"}], "descriptions": [{"lang": "en", "value": "A flaw was found in Keycloak. The cross-session verification proof is keyed only by (local userId,\nidpAlias) 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."}], "affected": [{"vendor": "Red Hat", "product": "Red Hat Build of Keycloak", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "rhbk/keycloak-rhel9", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:build_keycloak:"]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-9087", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2480172", "name": "RHBZ#2480172", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "datePublic": "2026-05-20T14:53:44.238Z", "problemTypes": [{"descriptions": [{"cweId": "CWE-639", "description": "Authorization Bypass Through User-Controlled Key", "lang": "en", "type": "CWE"}]}], "x_redhatCweChain": "CWE-639: Authorization Bypass Through User-Controlled Key", "workarounds": [{"lang": "en", "value": "To mitigate this issue, configure the affected identity provider to set `trustEmail=true`. This ensures that Keycloak trusts the email address provided by the upstream identity provider, bypassing the vulnerable verification flow. This mitigation should only be applied if the upstream identity provider is fully trusted to verify email addresses and prevent malicious account creation with existing email addresses. Configuration changes may require a Keycloak service restart or reload to take effect."}], "timeline": [{"lang": "en", "time": "2026-05-20T14:53:02.458Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-05-20T14:53:44.238Z", "value": "Made public."}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-05-20T16:13:03.022Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw was found in Keycloak. The cross-session verification proof is keyed only by (local userId,\nidpAlias) 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."}], "id": "CVE-2026-9087", "lastModified": "2026-05-20T17:32:35.827", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 1.2, "impactScore": 5.2, "source": "secalert@redhat.com", "type": "Primary"}]}, "published": "2026-05-20T17:16:32.207", "references": [{"source": "secalert@redhat.com", "url": "https://access.redhat.com/security/cve/CVE-2026-9087"}, {"source": "secalert@redhat.com", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2480172"}], "sourceIdentifier": "secalert@redhat.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-639"}], "source": "secalert@redhat.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": null}], "enrichment": {"confidence": 95.0, "confidence_source": "inferred", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 98.0, "source": "matching"}]}, "original": {"product": "Red Hat Build of Keycloak", "source": "cna", "vendor": "Red Hat"}, "product": "build_of_keycloak", "vendor": "redhat"}], "created": "2026-05-20T17:30:35.123612+00:00", "updated": "2026-05-20T17:30:35.421392+00:00", "vendors": ["redhat", "redhat$PRODUCT$build_of_keycloak"]}