RHSA-2026:97121 - Security Advisory

Topic

An update for unbound is now available for Red Hat Enterprise Linux 10.

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: Unbound DNS Cache Poisoning via Promiscuous Additional Section RRSet Acceptance (CVE-2026-42960)
• unbound: Unbound DNSSEC Validator NSEC3 Hash Calculation Limit Bypass via Negative Cache Code Path Leading to DoS (CVE-2026-42923)
• unbound: Unbound: Denial of Service due to locking inconsistency during RPZ XFR reload (CVE-2026-44608)

Bug Fix(es) and Enhancement(s):

• Update to latest 1.26 (JIRA:RHEL-246536)
• [RHEL-10][AppStream] Packages present in comps but missing from repo: unbound (JIRA:RHEL-171309)

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 10 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 10 x86_64
• Red Hat Enterprise Linux for IBM z Systems 10 s390x
• Red Hat Enterprise Linux for Power, little endian 10 ppc64le
• Red Hat Enterprise Linux for ARM 64 10 aarch64
• Red Hat CodeReady Linux Builder for x86_64 10 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian 10 ppc64le
• Red Hat CodeReady Linux Builder for ARM 64 10 aarch64
• Red Hat CodeReady Linux Builder for IBM z Systems 10 s390x

Fixes

• BZ - 2479821 - CVE-2026-42960 unbound: Unbound DNS Cache Poisoning via Promiscuous Additional Section RRSet Acceptance
• BZ - 2479825 - CVE-2026-42923 unbound: Unbound DNSSEC Validator NSEC3 Hash Calculation Limit Bypass via Negative Cache Code Path Leading to DoS
• BZ - 2480126 - CVE-2026-44608 unbound: Unbound: Denial of Service due to locking inconsistency during RPZ XFR reload
• RHEL-246536 - Update to latest 1.26

CVEs

• CVE-2026-42923
• CVE-2026-42960
• CVE-2026-44608

References

• https://access.redhat.com/security/updates/classification/#moderate
• https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/10/html/10.3_release_notes/index