RHSA-2026:72199 - Security Advisory

Topic

An update for unbound is now available for Red Hat Enterprise Linux 7 Extended Lifecycle Support.

Red Hat Product Security has rated this update as having a security impact of Critical. 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: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY (CVE-2026-81642)

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.

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 Server - Extended Life Cycle Support 7 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 s390x
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 ppc64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, little endian 7 ppc64le

Fixes

• BZ - 2535059 - CVE-2026-81642 unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY

CVEs

• CVE-2026-81642

References

• https://access.redhat.com/security/updates/classification/#critical