A heap-buffer-overflow flaw was found in Directory Server (389-ds-base). When a DN contains a legacy-quoted value, the server won't close the heap allocation allowing another call to refer to the same memory pointer causing a denial of service or an arbitrary memory write operation.

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Workaround

Denial of service is more reliably observed when heap debugging is enabled (for example AddressSanitizer or MALLOC_CHECK_=3), or depending on heap layout and subsequent memory allocator activity. For this reason Red Hat rates availability impact as Low (A:L) rather than High. There is no configuration switch to disable DN normalization for client-supplied DNs. The vulnerable code path is present in all currently supported 389-ds-base versions that ship the quoted-RDN parsing logic in dn.c.

History

Wed, 22 Jul 2026 13:30:00 +0000

Type Values Removed Values Added
Description A heap-buffer-overflow flaw was found in Directory Server (389-ds-base). When a DN contains a legacy-quoted value, the server won't close the heap allocation allowing another call to refer to the same memory pointer causing a denial of service or an arbitrary memory write operation.
Title 389-ds-base: 389-ds-base: heap-buffer-overflow in rdn_av_swap on quoted multivalued rdn
First Time appeared Redhat
Redhat directory Server
Redhat enterprise Linux
Weaknesses CWE-1220
CPEs cpe:/a:redhat:directory_server:11
cpe:/a:redhat:directory_server:12
cpe:/a:redhat:directory_server:13
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat directory Server
Redhat enterprise Linux
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-07-22T12:51:43.263Z

Reserved: 2026-07-22T12:11:52.389Z

Link: CVE-2026-16560

cve-icon Vulnrichment

No data.

cve-icon NVD

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cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses