RHSA-2026:75577HighCVSS 7.5

Red Hat Security Advisory: bind security update

Published
October 5, 2026
Last Modified
October 6, 2026

🔗 CVE IDs covered (5)

CVE-2026-81736 →CVE-2026-19666 →CVE-2026-19667 →CVE-2026-80274 →CVE-2026-81563 →

📋 Description

CVE-2026-19666 — bind: BIND: Denial of Service via malformed DNS64 responses CVE-2026-19667 — bind9: bind: BIND 9: Denial of Service via 16-bit length truncation in DNS negative cache handling CVE-2026-80274 — bind: BIND: Denial of Service via crafted DNSSEC reply CVE-2026-81563 — bind: BIND resolver: Denial of Service due to resource exhaustion in SVCB/HTTPS AliasMode processing CVE-2026-81736 — bind: BIND 9: Remote Denial of Service via cached SVCB/HTTPS AliasMode records

🎯 Affected products69

  • Red Hat Enterprise Linux AppStream (v. 10)
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • bind-32:9.18.33-15.el10_2.12.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-32:9.18.33-15.el10_2.12.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-32:9.18.33-15.el10_2.12.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-32:9.18.33-15.el10_2.12.src as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-32:9.18.33-15.el10_2.12.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-chroot-32:9.18.33-15.el10_2.12.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-chroot-32:9.18.33-15.el10_2.12.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-chroot-32:9.18.33-15.el10_2.12.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-chroot-32:9.18.33-15.el10_2.12.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-debuginfo-32:9.18.33-15.el10_2.12.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-debuginfo-32:9.18.33-15.el10_2.12.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • bind-debuginfo-32:9.18.33-15.el10_2.12.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-debuginfo-32:9.18.33-15.el10_2.12.ppc64le as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • bind-debuginfo-32:9.18.33-15.el10_2.12.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-debuginfo-32:9.18.33-15.el10_2.12.s390x as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • bind-debuginfo-32:9.18.33-15.el10_2.12.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-debuginfo-32:9.18.33-15.el10_2.12.x86_64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • bind-debugsource-32:9.18.33-15.el10_2.12.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-debugsource-32:9.18.33-15.el10_2.12.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • bind-debugsource-32:9.18.33-15.el10_2.12.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-debugsource-32:9.18.33-15.el10_2.12.ppc64le as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • bind-debugsource-32:9.18.33-15.el10_2.12.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-debugsource-32:9.18.33-15.el10_2.12.s390x as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • bind-debugsource-32:9.18.33-15.el10_2.12.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • bind-debugsource-32:9.18.33-15.el10_2.12.x86_64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • bind-devel-32:9.18.33-15.el10_2.12.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • bind-devel-32:9.18.33-15.el10_2.12.ppc64le as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • bind-devel-32:9.18.33-15.el10_2.12.s390x as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • +39 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 this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services. Workaround: To reduce the exposure to this vulnerability, configure BIND 9 to forward all DNS queries to trusted, non-vulnerable upstream DNS servers. This prevents the local `named` instance from directly interacting with potentially malicious authoritative servers. Example configuration in `named.conf`: ``` options { forwarders { 192.0.2.1; 192.0.2.2; }; forward only; }; ``` Replace `192.0.2.1` and `192.0.2.2` with the IP addresses of your trusted upstream DNS servers. After modifying the configuration, restart the `named` service for the changes to take effect. This configuration may impact DNS resolution if the configured forwarders are unavailable or do not provide comprehensive resolution. Workaround: To mitigate this issue, disable DNSSEC validation in the BIND resolver configuration. This can be achieved by setting `dnssec-enable no;` and `dnssec-validation no;` within the `options` block in `named.conf` or an included configuration file. A restart of the `named` service is required for the changes to take effect and may impact DNS resolution during the restart. Disabling DNSSEC validation will reduce the security posture of DNS resolution by removing integrity protection for DNS data. 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 the risk of this denial of service, configure BIND resolvers to restrict recursive queries to trusted clients only. This can be achieved by setting the `allow-recursion` option in the `named.conf` configuration file to specific IP addresses or networks. After modifying the configuration, the `named` service must be reloaded for the changes to take effect, which may temporarily interrupt DNS resolution.

🔗 References (8)