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389 Directory Server SASL UNBIND oversized packet overflows heap buffer after authenticated bind

Last refreshed2026-09-30

Status: NEW  |  Advisory ID: CVE-2026-11610

Key Details

CVECVE-2026-11610
CVSS Score / Version8.8 (High) / CVSS v3.1
Updated2026-07-08
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS Proseattack vector is network; attack complexity is low; privileges required is low; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high.
Classified asCWE-122 (Heap-based Buffer Overflow)

What to Know

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. (NVD)

References

SourceReference
NVDhttps://nvd.nist.gov/vuln/detail/CVE-2026-11610
CVEhttps://www.cve.org/CVERecord?id=CVE-2026-11610