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Medium

Keycloak SMTP Inject Vulnerability

  • Disclosed: 17.09.2025
  • Updated: 11.10.2026 12:22

Special characters used during e-mail registration may perform SMTP Injection and unexpectedly send short unwanted e-mails. The email is limited to 64 characters (limited local part of the email), so the attack is limited to very shorts emails (subject and little data, the example is 60 chars). This flaw's only direct consequence is an unsolicited email being sent from the Keycloak server. However, this action could be a precursor for more sophisticated attacks.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Java / Kotlin (Maven) org.keycloak:keycloak-services < 26.2.8, >= 26.3.0, < 26.3.3 26.2.8, 26.3.3

References

CVSS score 5.3/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness (CWE)
CWE-93
Platform
Java / Kotlin (Maven)
Package
org.keycloak:keycloak-services
Disclosed
17.09.2025
Updated
11.10.2026 12:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-m4j5-5x4r-2xp9 - 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: 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
  2. 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
  3. Keycloak has privilege escalation via improper scope mapping enforcement
    High · 7.3 CVE-2026-9795 < 26.6.4 26.6.4
  4. Keycloak: Open redirect when using wildcard valid redirect URIs in Keycloak
    High · 8.1 CVE-2026-7504 < 26.6.2 26.6.2
  5. 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
  6. Keycloak: Access token disclosure and implicit flow bypass via forged client data
    High · 7.1 CVE-2026-7571 < 26.6.2 26.6.2
  7. Keycloak: Privilege escalation via forged authorization codes due to SingleUseObjectProvider isolation flaw
    High · 7.4 CVE-2026-4282 < 26.5.7 26.5.7
  8. Keycloak: Application-Level DoS via Scope Processing
    High · 7.5 CVE-2026-4634 < 26.5.7 26.5.7
  9. Keycloak: UMA Policy Resource Injection Allows Unauthorized Cross-User Permission Grants
    High · 8.1 CVE-2026-4636 < 26.5.7 26.5.7
  10. Keycloak: Redirect URI validation bypass via ..;/ path traversal in OIDC auth endpoint
    High · 7.3 CVE-2026-3872 < 26.5.7 26.5.7
  11. Keycloak: Unauthorized authentication via disabled SAML Identity Provider
    High · 8.1 CVE-2026-2603 < 26.5.5 26.5.5
  12. 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
  13. 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
  14. 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
  15. Keycloak SMTP Inject Vulnerability this entry
    Medium · 5.3 CVE-2025-8419 < 26.2.8, >= 26.3.0, < 26.3.3 26.2.8, 26.3.3
  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
Show more (10) Showing 20 of 30

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