Keycloak: keycloak: user enumeration via differential error messages
Priority LOW 18CWE-209Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Partial Red Hat: 1 fixed, 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-209.
Summary
A flaw was found in Keycloak. A remote attacker can exploit differential error messages during the identity-first login flow when Organizations are enabled. This vulnerability allows an attacker to determine the existence of users, leading to information disclosure through user enumeration.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00422 36th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial org.keycloak:keycloak-services (Maven): 26.6.1, 26.4.12Red Hat: 1 advisoryRed Hat: 1 fixed, 1 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.4.12 | — | — | Not affected | CNA |
| Red Hat | Red Hat Build of Keycloak | — | — | No fix listed | CNA |
| — | org.keycloak:keycloak-services (Maven) | 26.5.0 to before 26.6.1 | 26.6.1 | Patch available | GHSA-rhgq-f8x5-j2jc |
| — | org.keycloak:keycloak-services (Maven) | before 26.4.12 | 26.4.12 | Patch available | GHSA-rhgq-f8x5-j2jc |
- Red Hat build of Keycloak 26.4.12 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Build of Keycloak VendorRed Hat Affected — Fixed in — No fix listed CNA
- org.keycloak:keycloak-services (Maven) Vendor— Affected 26.5.0 to before 26.6.1 Fixed in 26.6.1 Patch available GHSA-rhgq-f8x5-j2jc
- org.keycloak:keycloak-services (Maven) Vendor— Affected before 26.4.12 Fixed in 26.4.12 Patch available GHSA-rhgq-f8x5-j2jc
Remediation
- Fix · GHSA-rhgq-f8x5-j2jc org.keycloak:keycloak-services (Maven) Fixed in 26.6.1 Advisory →
- Fix · GHSA-rhgq-f8x5-j2jc org.keycloak:keycloak-services (Maven) Fixed in 26.4.12 Advisory →
Red Hat 1 advisory
- RHSA-2026:19596 Released 2026-05-20 · Red Hat rating ImportantRed Hat build of Keycloak 26.4.12 Security Update
- Red Hat build of Keycloak 26.4.12
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Build of Keycloak | Affected | No fix yet |
| Red Hat build of Keycloak 26.4.12 | Fixed | RHSA-2026:19596 |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-4633
- 2026-10-03 Alias added: GHSA-rhgq-f8x5-j2jc
- 2026-10-23 Affected versions changed · CNA
- 2026-10-23 1 new reference · CNA
- 2026-10-23 Fix available: RHSA-2026:19596 · Red Hat
- 2026-10-23 Fix available: Red Hat build of Keycloak 26.4.12 · Red Hat
- 2026-10-23 1 new reference · GHSA-rhgq-f8x5-j2jc
References
Exploit 1
Advisory 3
Other 5
- https://github.com/keycloak/keycloak/issues/47619
- https://github.com/keycloak/keycloak/pull/47635
- https://github.com/keycloak/keycloak/commit/b137016cc6dcfd9f59b2aa2e6d73af8b0ebf7c6e
- https://github.com/keycloak/keycloak/commit/b4558a874fa79341404ae4d2d8f240f22bfed340
- https://github.com/keycloak/keycloak
More Red Hat Build Of Keycloak vulnerabilities
- TI-2026-02223 Keycloak: keycloak: unauthorized authentication via disabled saml identity provider CVSS 3.1HIGH 8.1
- TI-2024-01049 Keycloak: path transversal in redirection validation CVSS 3.1HIGH 8.1
- TI-2026-13740 Keycloak-services: keycloak-services: saml idp-initiated broker login bypasses link-only restriction CVSS 3.1CRITICAL 9.8
- TI-2026-13741 Keycloak-services: keycloak-services: saml broker metadata import disables response signature validation CVSS 3.1CRITICAL 9.1
- TI-2026-13106 Keycloak-services: keycloak-services: dcr protocol mapper type-swap policy bypass allows privilege escalation CVSS 3.1HIGH 8.8
- TI-2026-02631 Authentication bypass in Red Hat build of Keycloak 26.2 CVSS 3.1HIGH 8.8
Sources
- CVE-2026-4633 · CVE Program
- CVE-2026-4633 · NVD
- FIRST EPSS
- GHSA-rhgq-f8x5-j2jc · GitHub Advisory Database · CC BY 4.0
- CVE-2026-4633 · Red Hat security data · CC BY 4.0
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