Amazon Linux 2 Security Advisory: ALAS2-2026-3853
Advisory Released Date: 2026-08-04
Advisory Updated Date: 2026-08-04
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. (CVE-2026-11610)
Affected Packages:
389-ds-base
Note:
This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.
Issue Correction:
Run yum update 389-ds-base or yum update --advisory ALAS2-2026-3853 to update your system.
aarch64:
389-ds-base-1.3.10.2-17.amzn2.0.8.aarch64
389-ds-base-libs-1.3.10.2-17.amzn2.0.8.aarch64
389-ds-base-devel-1.3.10.2-17.amzn2.0.8.aarch64
389-ds-base-snmp-1.3.10.2-17.amzn2.0.8.aarch64
389-ds-base-debuginfo-1.3.10.2-17.amzn2.0.8.aarch64
i686:
389-ds-base-1.3.10.2-17.amzn2.0.8.i686
389-ds-base-libs-1.3.10.2-17.amzn2.0.8.i686
389-ds-base-devel-1.3.10.2-17.amzn2.0.8.i686
389-ds-base-snmp-1.3.10.2-17.amzn2.0.8.i686
389-ds-base-debuginfo-1.3.10.2-17.amzn2.0.8.i686
src:
389-ds-base-1.3.10.2-17.amzn2.0.8.src
x86_64:
389-ds-base-1.3.10.2-17.amzn2.0.8.x86_64
389-ds-base-libs-1.3.10.2-17.amzn2.0.8.x86_64
389-ds-base-devel-1.3.10.2-17.amzn2.0.8.x86_64
389-ds-base-snmp-1.3.10.2-17.amzn2.0.8.x86_64
389-ds-base-debuginfo-1.3.10.2-17.amzn2.0.8.x86_64