[ CVE-2026-86345 · Published 2 Oct 2026 ]
Vulnerability in Red Hat Directory Server 11
CVSS 9.0
EPSS <1%No fix listed yet
[ Why it matters ]Priority signals
- Critical severity: CVSS 9.0
[ Description ]Official description
A flaw was found in 389-ds-base. The server does not discard plaintext bytes already buffered from a client connection when negotiating StartTLS, allowing an on-path attacker to inject a crafted LDAP message that is processed after the TLS upgrade and whose response is delivered to the client in place of the client's own pending operation's response, due to messageID collision. This can cause a client application to treat a failed authentication (bind) attempt as successful.
[ Fixes ]Fixes and patches
No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.