RHSA-2026:71487CriticalCVSS 9.8

Red Hat Security Advisory: unbound security update

Published
September 24, 2026
Last Modified
September 25, 2026

🔗 CVE IDs covered (3)

CVE-2026-81634 →CVE-2026-81642 →CVE-2026-82717 →

📋 Description

CVE-2026-81634 — unbound: Unbound: Heap buffer overflow via malicious DNSSEC response CVE-2026-81642 — unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY CVE-2026-82717 — unbound: Unbound: Remote Code Execution Vulnerability in CNAME Synthesis

🎯 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_8.8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-0:1.24.2-3.el9_8.8.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-0:1.24.2-3.el9_8.8.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-0:1.24.2-3.el9_8.8.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.8.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.8.i686 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.8.i686 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.8.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.8.ppc64le as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.8.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.8.s390x as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.8.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.8.x86_64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-0:1.24.2-3.el9_8.8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-0:1.24.2-3.el9_8.8.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-0:1.24.2-3.el9_8.8.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-0:1.24.2-3.el9_8.8.src as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-0:1.24.2-3.el9_8.8.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.8.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.8.i686 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.8.i686 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.8.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.8.ppc64le as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.8.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.8.s390x as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.8.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: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. Workaround: To mitigate this restrict Unbound to trusted clients and limit which upstream name servers it can query. If Unbound is unused, disable or remove the service. Apply process/cgroup limits to contain crash impact.

🔗 References (6)