CVE-2026-16560

Summary

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.

Affected Software

VendorProductVersion RangeStatus

Weaknesses

  • CWE-1220: Insufficient Granularity of Access Control

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.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References