Bug 2497697 (CVE-2026-14940)

Summary:	CVE-2026-14940 389-ds-base: 389-ds-base: heap-buffer-overflow in DN normalization via quoted multivalued RDN
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	aadhikar, bsmejkal, jachapma, mreynolds, progier, rhel-process-autobot, snegrini, spichugi, tbordaz, vashirov, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A heap-buffer-overflow flaw was found in 389 Directory Server (389-ds-base). When normalizing a Distinguished Name (DN) that contains a legacy-quoted value encoding a multivalued nested Relative Distinguished Name (RDN), the server can write past the end of a heap allocation while sorting RDN attribute-value pairs. An unauthenticated remote attacker can trigger this condition by sending an LDAP operation whose DN reaches the DN normalization routine, such as a search with a crafted base DN. This can corrupt heap memory and may cause denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2497718
Bug Blocks:

Description OSIDB Bzimport 2026-07-07 12:35:41 UTC

Valid heap-buffer-overflow in slapi_dn_normalize_ext() -> sort_rdn_avs() ->
rdn_av_swap() (ldap/servers/slapd/dn.c). Triggered when a DN contains a legacy-quoted
value encoding a multivalued nested RDN. On closing quote, nested attribute-value
tracking is not finalized; a subsequent separator can leave stale pointers that
produce overlapping berval entries. In-place sorting then writes past the heap
allocation in rdn_av_swap().
Reachable pre-auth via any LDAP operation whose DN is normalized (search base DN
confirmed). Reproduced on RHEL 9.8 (389-ds-base-2.8.0-7.el9_8) with reporter PoC.
Production behavior (no ASAN/MALLOC_CHECK_): malformed DN often returns err=34
(Invalid DN syntax); server continues. With MALLOC_CHECK_=3: general protection
fault in libc, ns-slapd terminates.