CVE-2026-78701

A flaw was found in 389-ds-base. A remote, authenticated attacker could exploit a vulnerability in the Simple Authentication and Security Layer (SASL) UNBIND process. By sending a specially crafted request, the attacker can cause a connection to stall, leading to resource exhaustion and a Denial of Service (DoS) for the server.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, restrict network access to the 389-ds-base service to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the LDAP ports (typically 389 for LDAP and 636 for LDAPS) to known, authorized IP addresses or subnets.

Example using firewalld:

# firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_IP_OR_SUBNET>" port port="389" protocol="tcp" accept'
# firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_IP_OR_SUBNET>" port port="636" protocol="tcp" accept'
# firewall-cmd --reload

Replace <TRUSTED_IP_OR_SUBNET> with the actual IP addresses or network ranges of your trusted clients. This action may impact legitimate clients if not configured correctly. A service restart is not required for firewall changes to take effect.