CVE-2026-107121

Keycloak-services: keycloak-services: smtp starttls plaintext credential and message downgrade

State
Published
Severity
6.5 Medium
Published
Oct 7, 2026
Updated
Oct 7, 2026
Reserved
Oct 7, 2026

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Description

A flaw was found in the SMTP email configuration handling of the keycloak-services component. When the STARTTLS option is enabled, Keycloak fails to strictly enforce an encrypted connection, allowing it to fall back to unencrypted communication if the encryption request is tampered with. An attacker who can intercept network traffic can exploit this to capture sensitive email credentials and message content in plain text.

Scores

CVSSScoreVectorSource
3.16.5 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:Nredhat

Weaknesses

  • CWE-319 Cleartext Transmission of Sensitive Information

Affected Products

ProductVersions
Red Hat Build of KeycloakRed Hat
    Red Hat Build of KeycloakRed Hat
      Red Hat Single Sign-On 7Red Hat

        References

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