CVE-2026-86345 Auth bypass in Red Hat Directory Server 11
An on-path attacker can forge LDAP authentication results by injecting messages during StartTLS negotiation, causing clients to accept failed logins as successful.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-86345?
CVE-2026-86345 is a critical authentication bypass vulnerability in Red Hat Directory Server 11, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-923
Which versions are affected by CVE-2026-86345?
How do I fix CVE-2026-86345?
Apply the vendor's patch.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-86345 being exploited?
There is no known exploitation of CVE-2026-86345 in the wild and no public exploit code.
Sources
Also known as AZL-107954, DEBIAN-CVE-2026-86345, GHSA-c4v7-fhgq-r988, UBUNTU-CVE-2026-86345.