CVE-2026-11787
published 2026-06-09CVE-2026-11787: A flaw was found in 389 Directory Server. The ldap_utf8prev() function reads bytes before the start of a buffer without bounds checking, causing a heap buffer…
PriorityP336medium6.3CVSS 3.1
AVNACLPRLUINSUCLILAL
EPSS
0.18%
7.4th percentile
A flaw was found in 389 Directory Server. The ldap_utf8prev() function reads bytes before the start of a buffer without bounds checking, causing a heap buffer over-read in string filter parsing that may influence internal filter processing behavior.
Affected
10 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| port389 | 389-ds-base | — | — |
| redhat-ds_11 | 389-ds-base | — | — |
| redhat-ds_12 | 389-ds-base | — | — |
| redhat | directory_server | — | — |
| redhat | directory_server | — | — |
| redhat | directory_server | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
CVSS provenance
nvdv3.16.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
vendor_redhat5.0MEDIUM
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Red Hat
389-ds-base: 389-ds-base: heap buffer over-read in ldap_utf8prev() via str2simple filter parsing
vendor_redhat·2026-04-16·CVSS 5.0
CVE-2026-11787 [MEDIUM] CWE-126 389-ds-base: 389-ds-base: heap buffer over-read in ldap_utf8prev() via str2simple filter parsing
389-ds-base: 389-ds-base: heap buffer over-read in ldap_utf8prev() via str2simple filter parsing
A flaw was found in 389 Directory Server. The ldap_utf8prev() function reads bytes before the start of a buffer without bounds checking, causing a heap buffer over-read in string filter parsing that may influence internal filter processing behavior.
Mitigation: No direct workaround addresses the code-level bug; network-level mitigations (proxies, WAFs, filter validation) do not apply. Mitigation measures to reduce exposure: restrict plugin configuration access (MEP originFilter, UID uniqueness nsUniqueAttribute, strict ACIs on cn=config); restrict Directory Manager access for ACI, MEP, or uniqueness plugin configuration; harden replication topology to restrict replication peers; monitor for a
GHSA
A flaw was found in 389 Directory Server.
ghsa_unreviewed·2026-06-09
CVE-2026-11787 [MEDIUM] CWE-126 A flaw was found in 389 Directory Server.
A flaw was found in 389 Directory Server. The ldap_utf8prev() function reads bytes before the start of a buffer without bounds checking, causing a heap buffer over-read in string filter parsing that may influence internal filter processing behavior.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-11787 389-ds-base: 389-ds-base: heap buffer over-read in ldap_utf8prev() via str2simple filter parsing [fedora-all]
bugzilla·2026-06-30·CVSS 6.3
CVE-2026-11787 [MEDIUM] CVE-2026-11787 389-ds-base: 389-ds-base: heap buffer over-read in ldap_utf8prev() via str2simple filter parsing [fedora-all]
CVE-2026-11787 389-ds-base: 389-ds-base: heap buffer over-read in ldap_utf8prev() via str2simple filter parsing [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
The ldap_utf8prev() function in 389 Directory Server unconditionally reads up to 6 bytes before a heap allocation because it lacks a lower-bound parameter. This API design flaw has existed since the Mozilla LDAP C SDK import and was symptomatically patched twice without fixing the root cause. Twenty call sites remain vulnerable to 1-6 byte heap over-reads.
Cannot be triggered via standard LDAP wire protocol (BER filters parsed separately), but
Bugzilla
CVE-2026-11787 389-ds-base: 389-ds-base: heap buffer over-read in ldap_utf8prev() via str2simple filter parsing
bugzilla·2026-06-05·CVSS 5.0
CVE-2026-11787 [MEDIUM] CVE-2026-11787 389-ds-base: 389-ds-base: heap buffer over-read in ldap_utf8prev() via str2simple filter parsing
CVE-2026-11787 389-ds-base: 389-ds-base: heap buffer over-read in ldap_utf8prev() via str2simple filter parsing
The ldap_utf8prev() function in 389 Directory Server unconditionally reads up to 6 bytes before a heap allocation because it lacks a lower-bound parameter. This API design flaw has existed since the Mozilla LDAP C SDK import and was symptomatically patched twice without fixing the root cause. Twenty call sites remain vulnerable to 1-6 byte heap over-reads.
Cannot be triggered via standard LDAP wire protocol (BER filters parsed separately), but internal callers processing attacker-influenced data (plugin configuration, ACI definitions, replication) are affected. ASan confirmed on aarch64; no crash on production binaries.
2026-06-09
Published