CVE-2026-107121 — Keycloak-services: keycloak-services: smtp starttls plaintext credential and message downgrade
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 encrypte…
Published: 2026-10-07 · CVSS: 6.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7