CVE-2026-11774

389-ds-base: 389-ds-base: integer overflow in sasl packet length bypasses size limit leading to heap buffer overflow

Published Jun 11, 2026 CVSS 3.1 · 7.6 High EPSS < 1% KEV · Not listed
Description
An integer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). In sasl_io_start_packet(), adding sizeof(uint32_t) to a crafted SASL packet length prefix of 0xFFFFFFFC causes unsigned wraparound to zero, bypassing the nsslapd-maxsasliosize limit and leading to a heap buffer overflow of up to approximately 2 megabytes of attacker-controlled data. After a successful SASL bind with integrity protection (SSF > 0), a remote attacker can cause a Denial of Service (DoS) or achieve Remote Code Execution (RCE). In FreeIPA and Red Hat Identity Management deployments, any domain user with a valid Kerberos ticket, enrolled host, or service account can trigger this vulnerability over the network. This flaw is independent of CVE-2025-14905, which patched schema.c only and did not modify sasl_io.c.

Remediation

Vendor Workaround

No complete workaround exists; nsslapd-maxsasliosize is bypassed by the integer overflow. Mitigations that reduce exposure: restrict SASL mechanisms (disable DIGEST-MD5 if not required; GSSAPI cannot be disabled in FreeIPA/IdM without breaking Kerberos authentication); firewall LDAP ports (389/636) to trusted networks; monitor for SASL-framed packets with length prefix 0xFFFFFFFC through 0xFFFFFFFF; enable audit logging (nsslapd-auditlog-logging-enabled: on); on RHEL 8, upgrading glibc reduces RCE exploitability but does not eliminate DoS.

Tracking

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Advisories

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History
Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:6 cpe:/o:redhat:rhel_els:6
Type Values Removed Values Added
First Time appeared Redhat rhel Eus
CPEs cpe:/a:redhat:rhel_eus:9.6::appstream
cpe:/a:redhat:rhel_eus:9.6::crb
Vendors & Products Redhat rhel Eus
References
Type Values Removed Values Added
First Time appeared Redhat enterprise Linux Eus
CPEs cpe:/a:redhat:directory_server_e4s:12.2::el9
cpe:/o:redhat:enterprise_linux_eus:10.0
Vendors & Products Redhat enterprise Linux Eus
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:directory_server:13.2::el10
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:rhel_e4s:9.2::appstream
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:directory_server:11
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:directory_server:11.9::el8
cpe:/a:redhat:directory_server_e4s:12.4::el9
cpe:/a:redhat:enterprise_linux:9::appstream
cpe:/a:redhat:enterprise_linux:9::crb
cpe:/o:redhat:enterprise_linux:10.2
References
Type Values Removed Values Added
First Time appeared Redhat rhel Aus
Redhat rhel Els
Redhat rhel Eus Long Life
CPEs cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:8::appstream
cpe:/a:redhat:rhel_aus:8.4::appstream
cpe:/a:redhat:rhel_aus:8.6::appstream
cpe:/a:redhat:rhel_eus_long_life:8.4::appstream
cpe:/a:redhat:rhel_eus_long_life:8.6::appstream
cpe:/o:redhat:rhel_els:7
Vendors & Products Redhat rhel Aus
Redhat rhel Els
Redhat rhel Eus Long Life
References
Type Values Removed Values Added
First Time appeared Redhat directory Server E4s
Redhat rhel E4s
Redhat rhel Tus
CPEs cpe:/a:redhat:directory_server_e4s:11.5::el8
cpe:/a:redhat:directory_server_e4s:11.7::el8
cpe:/a:redhat:rhel_e4s:8.8::appstream
cpe:/a:redhat:rhel_e4s:9.4::appstream
cpe:/a:redhat:rhel_tus:8.8::appstream
Vendors & Products Redhat directory Server E4s
Redhat rhel E4s
Redhat rhel Tus
References
Type Values Removed Values Added
First Time appeared Redhat redhat Directory Server
Vendors & Products Redhat redhat Directory Server
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description An integer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). In sasl_io_start_packet(), adding sizeof(uint32_t) to a crafted SASL packet length prefix of 0xFFFFFFFC causes unsigned wraparound to zero, bypassing the nsslapd-maxsasliosize limit and leading to a heap buffer overflow of up to approximately 2 megabytes of attacker-controlled data. After a successful SASL bind with integrity protection (SSF > 0), a remote attacker can cause a Denial of Service (DoS) or achieve Remote Code Execution (RCE). In FreeIPA and Red Hat Identity Management deployments, any domain user with a valid Kerberos ticket, enrolled host, or service account can trigger this vulnerability over the network. This flaw is independent of CVE-2025-14905, which patched schema.c only and did not modify sasl_io.c.
Title 389-ds-base: 389-ds-base: integer overflow in sasl packet length bypasses size limit leading to heap buffer overflow
First Time appeared Redhat
Redhat directory Server
Redhat enterprise Linux
Weaknesses CWE-190
CPEs cpe:/a:redhat:directory_server:11
cpe:/a:redhat:directory_server:12
cpe:/a:redhat:directory_server:13
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat directory Server
Redhat enterprise Linux
References
Metrics cvssV3_1

{'score': 7.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H'}