RHSA-2026:68292MediumCVSS 6.5

Red Hat Security Advisory: unbound security update

Published
September 16, 2026
Last Modified
September 16, 2026

🔗 CVE IDs covered (1)

CVE-2026-50252 →

📋 Description

CVE-2026-50252 — unbound: Unbound: DNS cache poisoning via UDP source port predictability

🎯 Affected products65

  • Red Hat Enterprise Linux AppStream (v. 9)
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-0:1.24.2-3.el9_8.6.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-0:1.24.2-3.el9_8.6.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-0:1.24.2-3.el9_8.6.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-0:1.24.2-3.el9_8.6.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.6.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.6.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.6.i686 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.6.i686 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.6.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.6.ppc64le as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.6.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.6.s390x as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.6.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.6.x86_64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-0:1.24.2-3.el9_8.6.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-0:1.24.2-3.el9_8.6.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-0:1.24.2-3.el9_8.6.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-0:1.24.2-3.el9_8.6.src as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-0:1.24.2-3.el9_8.6.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.6.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.6.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.6.i686 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.6.i686 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.6.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.6.ppc64le as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.6.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.6.s390x as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.6.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • +35 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: Disable the so-reuseport option by explicitly setting so-reuseport: no in your unbound.conf file. This prevents the deterministic mapping of worker threads to outbound UDP source ports, effectively stopping the cache poisoning vector. Additionally, restrict who can query the resolver using the access-control directive to reduce the overall attack surface, and restart the Unbound service to apply the changes.

🔗 References (4)