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High

Keycloak's unvalidated cross-origin messages in checkLoginIframe leads to DDoS

  • Disclosed: 17.04.2024
  • Updated: 11.10.2026 13:20

A potential security flaw in the "checkLoginIframe" which allows unvalidated cross-origin messages, enabling potential DDoS attacks. By exploiting this vulnerability, attackers could coordinate to send millions of requests in seconds using simple code, significantly impacting the application's availability without proper origin validation for incoming messages.

Acknowledgements

Special thanks to Adriano Márcio Monteiro from BRZTEC for reporting this issue and helping us improve our project.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Java / Kotlin (Maven) org.keycloak:keycloak-services < 22.0.10, >= 23.0.0, < 24.0.3 22.0.10, 24.0.3

References

CVSS score 7.4/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H
Weakness (CWE)
CWE-346
Platform
Java / Kotlin (Maven)
Package
org.keycloak:keycloak-services
Disclosed
17.04.2024
Updated
11.10.2026 13:20

Sources and licenses

OSV / GitHub Advisory Database - GHSA-m6q9-p373-g5q8 - CC BY 4.0

Vulnerability history: org.keycloak:keycloak-services

All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (98) in the archive
Total entries
98
First → latest
01.2022 08.2026
Without a fix
16
Exploited in attacks
0

Severity breakdown

  • Critical 3
  • High 26
  • Medium 51
  • Low 18

Disclosures per year

Severity:
  1. Keycloak's unvalidated cross-origin messages in checkLoginIframe leads to DDoS this entry
    High · 7.4 CVE-2024-1249 < 22.0.10, >= 23.0.0, < 24.0.3 22.0.10, 24.0.3
  2. Keycloak: Unauthenticated account takeover via reset-credentials flow bypass
    Critical · 9.1 CVE-2026-18963 >= 26.0.0, < 26.4.15, >= 26.5.0, < 26.6.6, >= 26.7.0, < 26.7.2 26.4.15, 26.6.6, 26.7.2
  3. Keycloak: Unauthorized access via improper validation of encrypted SAML assertions
    High · 7.7 CVE-2026-2092 <= 26.2.5, >= 26.3.0, <= 26.4.7, >= 26.5.0 no fix
  4. Keycloak has privilege escalation via improper scope mapping enforcement
    High · 7.3 CVE-2026-9795 < 26.6.4 26.6.4
  5. Keycloak: Open redirect when using wildcard valid redirect URIs in Keycloak
    High · 8.1 CVE-2026-7504 < 26.6.2 26.6.2
  6. Keycloak: Session fixation in OIDC login flow that can lead to account takeover
    High · 7.5 CVE-2026-7507 < 26.6.2 26.6.2
  7. Keycloak: Access token disclosure and implicit flow bypass via forged client data
    High · 7.1 CVE-2026-7571 < 26.6.2 26.6.2
  8. Keycloak: Privilege escalation via forged authorization codes due to SingleUseObjectProvider isolation flaw
    High · 7.4 CVE-2026-4282 < 26.5.7 26.5.7
  9. Keycloak: Application-Level DoS via Scope Processing
    High · 7.5 CVE-2026-4634 < 26.5.7 26.5.7
  10. Keycloak: UMA Policy Resource Injection Allows Unauthorized Cross-User Permission Grants
    High · 8.1 CVE-2026-4636 < 26.5.7 26.5.7
  11. Keycloak: Redirect URI validation bypass via ..;/ path traversal in OIDC auth endpoint
    High · 7.3 CVE-2026-3872 < 26.5.7 26.5.7
  12. Keycloak: Unauthorized authentication via disabled SAML Identity Provider
    High · 8.1 CVE-2026-2603 < 26.5.5 26.5.5
  13. Keycloak allows authentication using an Identity Provider (IdP) even after it has been disabled by an administrator
    High · 8.1 CVE-2026-3009 < 26.5.5 26.5.5
  14. Keycloak fails to verify if an Identity Provider (IdP) is enabled before issuing tokens
    High · 8.8 CVE-2026-1486 >= 26.5.0, < 26.5.3, < 26.4.9 26.5.3, 26.4.9
  15. Keycloak affected by improper invitation token validation
    High · 8.1 CVE-2026-1529 >= 26.5.0, < 26.5.3, < 26.2.13, >= 26.3.0, < 26.4.9 26.5.3, 26.2.13, 26.4.9
  16. Keycloak hostname verification
    High · 8.2 CVE-2025-3501 < 26.2.2 26.2.2
  17. org.keycloak:keycloak-services has Inefficient Regular Expression Complexity
    High · 6.5 CVE-2024-10270 < 24.0.9, >= 25.0.0, < 26.0.6 24.0.9, 26.0.6
  18. Keycloak has session fixation in Elytron SAML adapters
    High · 7.1 CVE-2024-7341 < 22.0.12, >= 23.0.0, < 24.0.7, >= 25.0.0, < 25.0.5 22.0.12, 24.0.7, 25.0.5
  19. Keycloak's admin API allows low privilege users to use administrative functions
    High · 8.1 CVE-2024-3656 < 24.0.5 24.0.5
  20. Keycloak exposes sensitive information in Pushed Authorization Requests (PAR)
    High · 7.5 CVE-2024-4540 < 24.0.5 24.0.5
  21. Keycloak path traversal vulnerability in redirection validation
    High · 8.1 CVE-2024-1132 < 22.0.10, >= 23.0.0, < 24.0.3 22.0.10, 24.0.3
Show more (8) Showing 21 of 29

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