CVE-2026-11787 389-ds-base: 389-ds-base: heap buffer over-read in ldap_utf8prev() via str2simple filter parsing
A heap buffer over-read in 389 Directory Server allows attackers to potentially crash the service or leak memory contents via crafted string filters.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-11787?
CVE-2026-11787 is a medium-severity memory corruption vulnerability in Redhat Enterprise Linux, published on 9 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-126
Which versions are affected by CVE-2026-11787?
It affects 3 products.
Products include Redhat 389 Directory Server, Redhat Directory Server, Redhat Enterprise Linux.
How do I fix CVE-2026-11787?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-11787 being exploited?
There is no known exploitation of CVE-2026-11787 in the wild and no public exploit code.
Other vulnerabilities in Redhat Enterprise Linux
- CVE-2026-11770 389-ds-base: 389-ds-base: pre-auth ldap filter injection in cleanallruv status check
- CVE-2026-15722 Memory corruption in Red Hat Directory Server 11.5 E4S for RHEL 8
- CVE-2026-9064 Denial of service in Red Hat Directory Server 11.5 E4S for RHEL 8
- CVE-2010-2222 Null dereference in Red Hat Directory Server
- CVE-2026-11611 389-ds-base: 389-ds-base: content sync plugin unbounded queue growth and race conditions
Sources
Also known as DEBIAN-CVE-2026-11787, GHSA-wjcg-9hh3-8323, UBUNTU-CVE-2026-11787.