Is CVE-2026-14940 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-14940 being exploited in the wild.

How severe is CVE-2026-14940?

Medium severity, with a CVSS score of 5.3, published 7 July 2026.

Which products and versions are affected?

389 Directory Server Project Directory Server 2.8.0-7.el9_8 and earlier.

Is there a fix for CVE-2026-14940?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-14940 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-14940?

Check whether you run 389 Directory Server Project Directory Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-14940: 389 Directory Server heap overflow in DN normalization

CVE-2026-14940 · Severity: medium · CVSS 5.3 · Published 2026-07-07

A security vulnerability has been identified in the 389 Directory Server, a widely used enterprise-grade directory service. An unauthenticated remote attacker can send a specially crafted request that causes the server to crash or behave unpredictably. This could lead to a denial of service, impacting the availability of authentication and directory services for the organization.

Technologies: 389 Directory Server Project Directory Server. Vendors: 389 Directory Server Project.

Quick answers

Is CVE-2026-14940 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-14940 being exploited in the wild.
How severe is CVE-2026-14940?: Medium severity, with a CVSS score of 5.3, published 7 July 2026.
Which products and versions are affected?: 389 Directory Server Project Directory Server 2.8.0-7.el9_8 and earlier.
Is there a fix for CVE-2026-14940?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-14940 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-14940?: Check whether you run 389 Directory Server Project Directory Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A heap-based buffer overflow exists in the slapi_dn_normalize_ext() function within ldap/servers/slapd/dn.c of 389-ds-base. The vulnerability is triggered during the normalization of a Distinguished Name (DN) that contains legacy-quoted values encoding multivalued nested Relative Distinguished Names (RDNs). When sorting RDN attribute-value pairs, the server fails to properly finalize nested tracking, leading to stale pointers and an out-of-bounds write in rdn_av_swap(). An unauthenticated attacker can exploit this by sending an LDAP operation with a crafted base DN, potentially causing a crash (SIGSEGV) or heap corruption. The issue has been reproduced on RHEL 9.8.

Affected products

389 Directory Server Project 389-ds-base 2.8.0-7.el9_8 and earlier
Red Hat Red Hat Directory Server 11, 12, 13
Red Hat Red Hat Enterprise Linux 7, 8, 9, 10

Timeline

2026-07-07: disclosed: Vulnerability reported and published to NVD

References

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