RHSA-2026:36777HighCVSS 7.5

Red Hat Security Advisory: unbound security update

Published
July 8, 2026
Last Modified
August 21, 2026

🔗 CVE IDs covered (4)

CVE-2026-40622 →CVE-2026-41292 →CVE-2026-42534 →CVE-2026-44390 →

📋 Description

CVE-2026-40622 — unbound: Unbound: Cache manipulation via 'ghost domain names' attack CVE-2026-41292 — unbound: Unbound: Denial of Service via excessive EDNS options CVE-2026-42534 — unbound: Unbound: Denial of Service due to degraded resolution performance in jostle logic CVE-2026-44390 — unbound: Unbound: Denial of Service due to excessive resource consumption with large DNS Resource Record Sets

🎯 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_8.2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-0:1.24.2-3.el9_8.2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-0:1.24.2-3.el9_8.2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-0:1.24.2-3.el9_8.2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.2.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.2.i686 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.2.i686 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.2.ppc64le as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.2.s390x as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • python3-unbound-debuginfo-0:1.24.2-3.el9_8.2.x86_64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-0:1.24.2-3.el9_8.2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-0:1.24.2-3.el9_8.2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-0:1.24.2-3.el9_8.2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-0:1.24.2-3.el9_8.2.src as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-0:1.24.2-3.el9_8.2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.2.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.2.i686 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.2.i686 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.2.ppc64le as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.2.s390x as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • unbound-debuginfo-0:1.24.2-3.el9_8.2.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: To mitigate the risk of denial of resolution service, restrict Unbound's network exposure. Configure Unbound to only accept queries from trusted internal networks and to forward its own queries exclusively to trusted, well-maintained upstream DNS servers. This reduces the opportunity for an adversary to interact with or act as a malicious upstream for the vulnerable Unbound instance. After modifying Unbound's configuration, a service restart is required for changes to take effect. This may temporarily interrupt DNS resolution services. 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.

🔗 References (7)