CVE-2026-16560 PUBLISHED

389-ds-base: 389-ds-base: heap-buffer-overflow in rdn_av_swap on quoted multivalued rdn

Assigner: redhat
Reserved: 22.07.2026 Published: 22.07.2026 Updated: 22.07.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS Score: 5.3

Product Status

Vendor Red Hat
Product Red Hat Directory Server 11
Versions Default: affected
Vendor Red Hat
Product Red Hat Directory Server 12
Versions Default: affected
Vendor Red Hat
Product Red Hat Directory Server 13
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 10
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 6
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 7
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 8
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 9
Versions Default: affected

Workarounds

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.

Credits

  • Red Hat would like to thank Denis Rastyogin (ALT Linux) for reporting this issue.

References

Problem Types

  • Insufficient Granularity of Access Control CWE