{"id":"CVE-2026-16560","title":"389-ds-base: 389-ds-base: heap-buffer-overflow in rdn_av_swap on quoted multivalued rdn","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 s…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","cvssSource":"cna","cwe":["CWE-1220"],"vendor":"Red Hat","product":"redhat-ds:11/389-ds-base","affected":["redhat-ds:11/389-ds-base (all versions)","redhat-ds:12/389-ds-base (all versions)","389-ds-base (all versions)","389-ds-base (all versions)","389-ds-base (all versions)","389-ds-base (all versions)","389-ds-base (all versions)","389-ds-base (all versions)"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-07-22T18:01:40.896935Z"},"published":"2026-07-22","updated":"2026-11-05","sourceUpdated":"2026-11-05T19:24:06.831Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-16560","references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-16560"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2506102","label":"RHBZ#2506102"}],"tags":["cve.org"],"epss":0.00396,"epssPercentile":0.33993,"ingestedAt":"2026-11-05T22:38:31.535Z","slug":"CVE-2026-16560","body":"## Overview\n\nA 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.\n\n## Affected\n\n- `redhat-ds:11/389-ds-base (all versions)`\n- `redhat-ds:12/389-ds-base (all versions)`\n- `389-ds-base (all versions)`\n- `389-ds-base (all versions)`\n- `389-ds-base (all versions)`\n- `389-ds-base (all versions)`\n- `389-ds-base (all versions)`\n- `389-ds-base (all versions)`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n### Workarounds\n\nDenial of service is more reliably observed\nwhen heap debugging is enabled (for example AddressSanitizer or MALLOC_CHECK_=3),\nor depending on heap layout and subsequent memory allocator activity. For this\nreason Red Hat rates availability impact as Low (A:L) rather than High.\nThere is no configuration switch to disable DN normalization for client-supplied DNs.\nThe vulnerable code path is present in all currently supported 389-ds-base versions\nthat ship the quoted-RDN parsing logic in dn.c.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}