CVE-2026-11774

Summary

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.

Affected Software

VendorProductVersion RangeStatus
Red HatRed Hat Directory Server 11.5 E4S for RHEL 88060020260702180044.0ca98e7e < *unaffected
Red HatRed Hat Directory Server 11.7 E4S for RHEL 88080020260702180836.f969626e < *unaffected
Red HatRed Hat Directory Server 11.9 for RHEL 88100020260702145313.37ed7c03 < *unaffected
Red HatRed Hat Directory Server 12.2 E4S for RHEL 99020020260703060155.1674d574 < *unaffected
Red HatRed Hat Directory Server 12.4 E4S for RHEL 99040020260703055735.1674d574 < *unaffected
Red HatRed Hat Enterprise Linux 100:3.2.0-8.el10_2 < *unaffected
Red HatRed Hat Enterprise Linux 10.0 Extended Update Support0:3.0.6-19.el10_0 < *unaffected
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle Support0:1.3.11.1-13.el7_9 < *unaffected
Red HatRed Hat Enterprise Linux 88100020260626120929.25e700aa < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support8040020260629123121.96015a92 < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On8040020260629123121.96015a92 < *unaffected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support8060020260626130540.824efc52 < *unaffected
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On8060020260626130540.824efc52 < *unaffected
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Service8080020260630025241.6dbb3803 < *unaffected
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP Solutions8080020260630025241.6dbb3803 < *unaffected
Red HatRed Hat Enterprise Linux 90:2.8.0-8.el9_8 < *unaffected
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP Solutions0:2.2.4-19.el9_2 < *unaffected
Red HatRed Hat Enterprise Linux 9.4 Update Services for SAP Solutions0:2.4.5-26.el9_4 < *unaffected
Red HatRed Hat Enterprise Linux 9.6 Extended Update Support0:2.6.1-22.el9_6 < *unaffected
Red HatRed Hat Directory Server 13.21783452100 < *unaffected

Weaknesses

  • CWE-190: Integer Overflow or Wraparound

Workarounds

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.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

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

Additional References

References