RHSA-2026:26465HighCVSS 7.5

Red Hat Security Advisory: 389-ds-base security update

Published
June 17, 2026
Last Modified
November 6, 2026

🔗 CVE IDs covered (1)

CVE-2026-9064 →

📋 Description

CVE-2026-9064 — 389-ds-base: 389-ds-base: unbounded LDAP controls count in get_ldapmessage_controls_ext() causes CPU and heap amplification (remote DoS)

🎯 Affected products52

  • Red Hat CodeReady Linux Builder EUS (v.9.6)
  • Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-0:2.6.1-21.el9_6.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-0:2.6.1-21.el9_6.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-0:2.6.1-21.el9_6.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-0:2.6.1-21.el9_6.src as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-0:2.6.1-21.el9_6.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-debuginfo-0:2.6.1-21.el9_6.aarch64 as a component of Red Hat CodeReady Linux Builder EUS (v.9.6)
  • 389-ds-base-debuginfo-0:2.6.1-21.el9_6.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-debuginfo-0:2.6.1-21.el9_6.ppc64le as a component of Red Hat CodeReady Linux Builder EUS (v.9.6)
  • 389-ds-base-debuginfo-0:2.6.1-21.el9_6.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-debuginfo-0:2.6.1-21.el9_6.s390x as a component of Red Hat CodeReady Linux Builder EUS (v.9.6)
  • 389-ds-base-debuginfo-0:2.6.1-21.el9_6.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-debuginfo-0:2.6.1-21.el9_6.x86_64 as a component of Red Hat CodeReady Linux Builder EUS (v.9.6)
  • 389-ds-base-debuginfo-0:2.6.1-21.el9_6.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-debugsource-0:2.6.1-21.el9_6.aarch64 as a component of Red Hat CodeReady Linux Builder EUS (v.9.6)
  • 389-ds-base-debugsource-0:2.6.1-21.el9_6.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-debugsource-0:2.6.1-21.el9_6.ppc64le as a component of Red Hat CodeReady Linux Builder EUS (v.9.6)
  • 389-ds-base-debugsource-0:2.6.1-21.el9_6.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-debugsource-0:2.6.1-21.el9_6.s390x as a component of Red Hat CodeReady Linux Builder EUS (v.9.6)
  • 389-ds-base-debugsource-0:2.6.1-21.el9_6.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-debugsource-0:2.6.1-21.el9_6.x86_64 as a component of Red Hat CodeReady Linux Builder EUS (v.9.6)
  • 389-ds-base-debugsource-0:2.6.1-21.el9_6.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-devel-0:2.6.1-21.el9_6.aarch64 as a component of Red Hat CodeReady Linux Builder EUS (v.9.6)
  • 389-ds-base-devel-0:2.6.1-21.el9_6.ppc64le as a component of Red Hat CodeReady Linux Builder EUS (v.9.6)
  • 389-ds-base-devel-0:2.6.1-21.el9_6.s390x as a component of Red Hat CodeReady Linux Builder EUS (v.9.6)
  • 389-ds-base-devel-0:2.6.1-21.el9_6.x86_64 as a component of Red Hat CodeReady Linux Builder EUS (v.9.6)
  • 389-ds-base-libs-0:2.6.1-21.el9_6.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-libs-0:2.6.1-21.el9_6.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • 389-ds-base-libs-0:2.6.1-21.el9_6.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • +22 more not shown

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: Restrict network access to the LDAP port (389/tcp, 636/tcp) to trusted networks only using firewall rules or network ACLs. This prevents untrusted remote attackers from reaching the vulnerable code path. Optionally, lower the nsslapd-maxbersize configuration parameter to reduce the maximum BER message size accepted by the server. Note that this caps bytes, not the number of controls, and does not fully eliminate the amplification. Setting it too low may impact legitimate LDAP operations with large payloads.

🔗 References (4)