CVE-2026-11791 — MEDIUM (5.0)

Vulnerability Description

A flaw was found in 389 Directory Server. During schema reload, the attr_syntax_swap_ht() function unconditionally frees attribute syntax information nodes, bypassing the refcount-based deferred deletion used elsewhere in the attribute syntax subsystem. If an administrator triggers schema reload while concurrent LDAP query traffic is active, worker threads may access freed memory, resulting in use-after-free or double-free and a denial of service (server crash).

CVSS Score

5.0

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:H

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

HIGH

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

LOW

Availability

HIGH

Affected Products

Vendor	Product	Versions
Redhat	Directory Server	11.0
Redhat	389 Directory Server	-
Redhat	Enterprise Linux	7.0

Related Weaknesses (CWE)

CWE-416

References

https://access.redhat.com/security/cve/CVE-2026-11791MitigationVendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2485414Issue TrackingVendor Advisory

FAQ

What is CVE-2026-11791?

CVE-2026-11791 is a vulnerability with a CVSS score of 5.0 (MEDIUM). A flaw was found in 389 Directory Server. During schema reload, the attr_syntax_swap_ht() function unconditionally frees attribute syntax information nodes, bypassing the refcount-based deferred delet...

How severe is CVE-2026-11791?

CVE-2026-11791 has been rated MEDIUM with a CVSS base score of 5.0/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-11791?

Check the references section above for vendor advisories and patch information. Affected products include: Redhat Directory Server, Redhat 389 Directory Server, Redhat Enterprise Linux.