RHSA-2026:18931 - Security Advisory

Topic

An update for unbound is now available for Red Hat Enterprise Linux 9.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The unbound packages provide a validating, recursive, and caching DNS or DNSSEC resolver.

Security Fix(es):

• unbound: DNSBomb vulnerability (CVE-2024-33655)
• unbound: Unbound domain hijacking via promiscuous records (CVE-2025-11411)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 9 Release Notes linked from the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 9 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 9.8 x86_64
• Red Hat Enterprise Linux for IBM z Systems 9 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.8 s390x
• Red Hat Enterprise Linux for Power, little endian 9 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.8 ppc64le
• Red Hat Enterprise Linux for ARM 64 9 aarch64
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.8 aarch64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.8 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.8 x86_64
• Red Hat CodeReady Linux Builder for x86_64 9 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian 9 ppc64le
• Red Hat CodeReady Linux Builder for ARM 64 9 aarch64
• Red Hat CodeReady Linux Builder for IBM z Systems 9 s390x
• Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support 9.8 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support 9.8 ppc64le
• Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support 9.8 s390x
• Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support 9.8 aarch64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.8 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.8 s390x
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.8 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.8 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.8 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.8 s390x

Fixes

• BZ - 2279942 - CVE-2024-33655 unbound: DNSBomb vulnerability
• BZ - 2405706 - CVE-2025-11411 unbound: Unbound domain hijacking via promiscuous records
• RHEL-77716 - unbound: New root trust anchor key for DNSSEC

CVEs

• CVE-2024-33655
• CVE-2025-11411

References

• https://access.redhat.com/security/updates/classification/#moderate
• https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/9/html/9.8_release_notes/index