Build Of KeycloakApplication · Redhat
CVE-2026-9087
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceKeycloak's cross-session verification proof is keyed only by local userId and idpAlias, but is not bound to the specific upstream identity that was actually verified. This allows a second upstream account on the same IdP to consume the verification proof and get linked to the victim's local account, enabling account takeover or privilege escalation via identity provider account linking.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Build Of KeycloakApplication
all versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm Keycloak versionAccess Keycloak admin console or check the running container/service version. Compare the installed version against the affected ranges (Red Hat Build of Keycloak all versions).Affected if The installation is any version of Red Hat Build of Keycloak.
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Identify configured Identity ProvidersIn Keycloak admin console, navigate to Identity Providers section. List all configured IdP instances (verify the idpAlias values for each).Affected if Any IdP is configured and enabled in the realm.
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Verify IdP linking feature is enabledCheck realm settings or authentication flows for First Broker Login or Account Linking flows. Confirm the linking flow that uses verification proofs is active.Affected if IdP linking or first broker login flow is enabled for the realm.
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Inspect existing IdP account linksQuery user federation or user storage to examine which users have IdP identities linked. For each linked account, verify the mapping between local userId and idpAlias.Affected if Any user accounts have IdP identities linked to them (local userId linked to idpAlias).
A user is affected if they are running any version of Red Hat Build of Keycloak with at least one IdP configured and the account linking feature enabled, as the verification proof is not bound to the upstream identity identifier.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataThe verification proof must be bound to the specific upstream identity (e.g., the IdP's user identifier) in addition to the local userId and idpAlias, ensuring only the originally verified IdP account can complete the linking process.
Fix this in Build Of Keycloak
Scoped from the published advisory
- Consultation8.0 h
- Implementation16.0 h
- Testing12.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $12,352.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-9087 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-9087 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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