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High RLSA-2026:54509 6 CVEs

Important: bind9.16 security update

Published Aug 14, 2026 · Updated Aug 14, 2026

Ecosystem: Rocky Linux

Summary

The Berkeley Internet Name Domain (BIND) is an implementation of the Domain Name System (DNS) protocols. BIND includes a DNS server (named); a resolver library (routines for applications to use when interfacing with DNS); and tools for verifying that the DNS server is operating correctly.

Security Fix(es):

* bind9: bind: Potential wildcard CNAME RPZ policy bypass (CVE-2026-11331)

* bind: bind9: DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field (CVE-2026-13321)

* bind: bind9: Potential memory usage beyond configured limits (CVE-2026-11622)

* bind: bind9: Cache poisoning via label count discrepancy, RRSIG, wildcards (CVE-2026-11721)

* bind: bind9: Unexpected exit with NSEC and NSEC3 both present (CVE-2026-13204)

* bind: bind9: Incorrect acceptance of NSEC3 records (CVE-2026-10723)

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 bind9.16 2:9.16.23-0.22.el8_10.12

Vulnerabilities 6

  • High 8.6
    CVE-2026-13321

    DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field

    The BIND resolver accepts validly-signed NSEC records where the "Next Domain Name" field points outside the signer's zone. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1,…

    ISC BIND 9 bind9 bind9 Debian Ubuntu Azure Linux Alpine
  • High 7.5
    CVE-2026-11331

    Potential wildcard CNAME RPZ policy bypass

    An attacker who knows (or guesses) that a resolver uses RPZ with wildcard CNAME policies can craft query names long enough to trigger a NAMETOOLONG error condition during RPZ processing. This is not handled correctly and may lead to defeating the RPZ rule. It…

    ISC BIND 9 bind9 bind9 Debian Ubuntu Azure Linux Alpine
  • High 7.5
    CVE-2026-11622

    Potential memory usage beyond configured limits

    A DNSSEC validating resolver that is under a random subdomain attack against a DNSSEC-signed zone can suffer from runaway memory usage. The attacker needs to be able to send queries faster than the resolver can perform validation. The increased memory usage c…

    ISC BIND 9 bind9 bind9 Debian Ubuntu Azure Linux Alpine
  • High 7.5
    CVE-2026-11721

    Cache poisoning possible with label count discrepancy, RRSIG, and wildcards

    It is possible for an attacker's zone to respond to a query with an RRSIG that has a smaller number of labels than the zone in which the RRSIG is contained. This causes `named` to produce a wildcard name for a zone that is shorter than the attacker's zone, wh…

    ISC BIND 9 bind9 bind9 Debian Ubuntu Azure Linux Alpine
  • High 7.5
    CVE-2026-13204

    Unexpected exit in certain situations with NSEC and NSEC3 both present

    If a provably insecure domain is covered by both an NSEC and NSEC3 record at the parent, and there exist an RRSIG for only one of these types, then BIND may exit unexpectedly with an assertion while validating this proof. This issue affects BIND 9 versions 9.…

    ISC BIND 9 bind9 bind9 Debian Ubuntu Azure Linux Alpine
  • Medium 6.8
    CVE-2026-10723

    Incorrect acceptance of NSEC3 records

    BIND may accept incorrect child-zone NSEC3 records as valid, which could allow an attacker to forge authenticated NXDOMAIN responses. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through …

    ISC BIND 9 bind9 bind9 Debian Ubuntu Azure Linux Alpine

References

  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2503721
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2504166
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2504298
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2504338
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2504447
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2504560
  • advisory
    https://access.redhat.com/errata/RHSA-2026:54509