Skip to content
OpenAdvisories
High RLSA-2026:24365 2 CVEs

Important: unbound security update

Published Jun 11, 2026 · Updated Jun 11, 2026

Summary

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

Security Fix(es):

* unbound: Heap overflow and crash with multiple nsid, cookie, padding EDNS options (CVE-2026-42944)

* unbound: Unbound DNSSEC Validator Denial of Service via Incorrect Write Offset Counter in Chase-Reply Messages (CVE-2026-42959)

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.

Fixed packages 1

ReleasePackageFixed in
Rocky Linux · 8 unbound 0:1.16.2-5.11.el8_10

Vulnerabilities 2

  • High 8.7

    Heap overflow with multiple NSID, COOKIE, PADDING EDNS options

    NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options ('nsid', 'answer-cookie', '…

  • High 8.7

    Crash during DNSSEC validation of malicious content

    NLnet Labs Unbound up to and including version 1.25.0 has a denial of service vulnerability in the DNSSEC validator that can lead to a crash given malicious upstream replies. When Unbound constructs chase-reply messages for validation, the code uses the wrong…

References

  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2479774
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2479806