CVE-2026-11610 389-ds-base: 389-ds-base: heap buffer overflow in sasl_io_recv() via padded sasl unbind
An authenticated attacker can cause a denial of service in 389 Directory Server by sending a crafted oversized LDAP UNBIND packet that triggers a heap buffer overflow.
- 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-2026-11610?
CVE-2026-11610 is a high-severity memory corruption vulnerability in 389ds 389-ds-base, published on 7 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A heap buffer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). After a successful SASL bind with integrity protection (SSF > 0), an authenticated attacker can send a specially crafted oversized LDAP UNBIND packet that is copied into a 512-byte heap receive buffer without a bounds check in sasl_io_recv() in sasl_io.c. This allows up to approximately 2 megabytes of attacker-controlled data to overflow the buffer, causing a denial of service (server crash). In FreeIPA and Red Hat Identity Management deployments, any domain user with a valid Kerberos ticket, any enrolled host, or any service account can trigger this vulnerability over the network after authenticating via GSSAPI. The vulnerable code path has existed since approximately 2013 (389-ds-base 1.3.2) and was not addressed by the CVE-2025-14905 fix, which patched a separate heap overflow in schema.c only.
Weakness: CWE-122
Which versions are affected by CVE-2026-11610?
How do I fix CVE-2026-11610?
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-2026-11610 being exploited?
There is no known exploitation of CVE-2026-11610 in the wild and no public exploit code.
Sources
Also known as AZL-92069, CLSA-2026-1784796076, DEBIAN-CVE-2026-11610, GHSA-2g8g-f92j-g4gq, UBUNTU-CVE-2026-11610.