CVE-2026-14940: redhat 389_directory_server Heap-based Buffer Overflow

Vulnerability summary

CVE-2026-14940 is a medium (CVSS 5.3) Heap-based Buffer Overflow vulnerability in redhat 389_directory_server. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 40.6% of scored vulnerabilities.

Timeline

1. 07-07-2026
   PublishedVulnerability first disclosed.
2. 07-07-2026
   Last modifiedVulnerability information updated.

Description

A heap-buffer-overflow flaw was found in 389 Directory Server (389-ds-base). When normalizing a Distinguished Name (DN) that contains a legacy-quoted value encoding a multivalued nested Relative Distinguished Name (RDN), the server can write past the end of a heap allocation while sorting RDN attribute-value pairs. An unauthenticated remote attacker can trigger this condition by sending an LDAP operation whose DN reaches the DN normalization routine, such as a search with a crafted base DN. This can corrupt heap memory and may cause denial of service.

• CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().