Heap Buffer Overflow in 389Directory Server DN Normalization
CVE-2026-14940 Published on July 7, 2026
389-ds-base: 389-ds-base: heap-buffer-overflow in dn normalization via quoted multivalued rdn
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.
Vulnerability Analysis
CVE-2026-14940 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a small impact on availability.
Timeline
Reported to Red Hat.
Made public. 35 days later.
Weakness Type
Heap-based Buffer Overflow
A 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().
Products Associated with CVE-2026-14940
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