CVE-2026-107121

MEDIUM CVSS 3.1: 6.5 EPSS 0.08%
Updated Oct 07, 2026
Red Hat
Parameter Value
CVSS 6.5 (MEDIUM)
Type CWE-319 (Cleartext Transmission)
Vendor Red Hat
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
Low
Partial data modification
Availability
None
No disruption

CVSS Vector v3.1

Vulnerable Products

red hat:red hat build of keycloak red hat:red hat single sign-on 7