CVE-2026-11610: 389-ds-base: 389-ds-base: heap buffer overflow in sasl_io_recv() via padded sasl unbind

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-07 · updated 2026-07-08
Weakness: CWE-122

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.

Affected products

389ds 389-ds-base: from 1.3.2 through 3.3.0
Red Hat Directory Server 11.5 E4S for RHEL 8: all versions — fixed in 8060020260702180044.0ca98e7e
Red Hat Directory Server 11.7 E4S for RHEL 8: all versions — fixed in 8080020260702180836.f969626e
Red Hat Directory Server 11.9 for RHEL 8: all versions — fixed in 8100020260702145313.37ed7c03
Red Hat Directory Server 12: all versions
Red Hat Directory Server 12.2 E4S for RHEL 9: all versions — fixed in 9020020260703060155.1674d574
Red Hat Directory Server 12.4 E4S for RHEL 9: all versions — fixed in 9040020260703055735.1674d574
Red Hat Directory Server 13.2: all versions — fixed in 1783452100
Red Hat Enterprise Linux 10: all versions — fixed in 0:3.2.0-8.el10_2
Red Hat Enterprise Linux 10.0 Extended Update Support: all versions — fixed in 0:3.0.6-19.el10_0
Red Hat Enterprise Linux 6: all versions
Red Hat Enterprise Linux 7 Extended Lifecycle Support: all versions — fixed in 0:1.3.11.1-13.el7_9
Red Hat Enterprise Linux 8: all versions — fixed in 8100020260626120929.25e700aa
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support: all versions — fixed in 8040020260629123121.96015a92
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On: all versions — fixed in 8040020260629123121.96015a92
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: all versions — fixed in 8060020260626130540.824efc52
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On: all versions — fixed in 8060020260626130540.824efc52
Red Hat Enterprise Linux 8.8 Telecommunications Update Service: all versions — fixed in 8080020260630025241.6dbb3803
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions: all versions — fixed in 8080020260630025241.6dbb3803
Red Hat Enterprise Linux 9: all versions — fixed in 0:2.8.0-8.el9_8
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions: all versions — fixed in 0:2.2.4-19.el9_2
Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions: all versions — fixed in 0:2.4.5-26.el9_4
Red Hat Enterprise Linux 9.6 Extended Update Support: all versions — fixed in 0:2.6.1-22.el9_6

How to fix

Upgrade to a fixed version: Red Hat Directory Server 11.5 E4S for RHEL 8 8060020260702180044.0ca98e7e; Red Hat Directory Server 11.7 E4S for RHEL 8 8080020260702180836.f969626e; Red Hat Directory Server 11.9 for RHEL 8 8100020260702145313.37ed7c03; Red Hat Directory Server 12.2 E4S for RHEL 9 9020020260703060155.1674d574; Red Hat Directory Server 12.4 E4S for RHEL 9 9040020260703055735.1674d574; Red Hat Directory Server 13.2 1783452100; Red Hat Enterprise Linux 10 0:3.2.0-8.el10_2; Red Hat Enterprise Linux 10.0 Extended Update Support 0:3.0.6-19.el10_0; Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:1.3.11.1-13.el7_9; Red Hat Enterprise Linux 8 8100020260626120929.25e700aa; Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 8040020260629123121.96015a92; Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 8040020260629123121.96015a92. Check the vendor advisory for mitigations.

References

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