Red Hat - Red Hat Directory Server 11 - CRITICAL - CVE-2026-86345. A vulnerability has been identified in the 389 Directory Server where plaintext bytes from a client connection are not properly discarded during the StartTLS negotiation. This oversight allows an on-path attacker to inject a crafted LDAP message that can interfere with the TLS upgrade process. As a result, when the server processes the malicious message post-upgrade, the response may be delivered to the client as if it were part of its own pending operation. This can mislead client applications into erroneously treating failed authentication attempts as successful, posing significant risks to data integrity and system security.