ALAS2-2026-3854

Amazon Linux 2 Security Advisory: ALAS2-2026-3854
Advisory Released Date: 2026-08-04
Advisory Updated Date: 2026-08-04
Severity: Important
Issue Overview:

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 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1. (CVE-2026-10723)

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 can be orders of magnitude beyond the limit configured in the `max-cache-size` parameter.
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, and 9.20.9-S1 through 9.20.24-S1. (CVE-2026-11622)

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, which can result in cache poisoning. For this attack to have any effect, the resolver under attack must have set `synth-from-dnssec yes;` (which is the default).
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, and 9.20.9-S1 through 9.20.24-S1. (CVE-2026-11721)

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 9.11.0 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, and 9.20.9-S1 through 9.20.24-S1. (CVE-2026-13204)

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, and 9.20.9-S1 through 9.20.24-S1. (CVE-2026-13321)


Affected Packages:

bind


Note:

This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.


Issue Correction:
Run yum update bind or yum update --advisory ALAS2-2026-3854 to update your system.

New Packages:
aarch64:
    bind-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-pkcs11-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-pkcs11-utils-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-pkcs11-libs-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-pkcs11-devel-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-sdb-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-libs-lite-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-libs-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-utils-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-devel-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-lite-devel-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-chroot-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-sdb-chroot-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-export-libs-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-export-devel-9.11.4-26.P2.amzn2.13.17.aarch64
    bind-debuginfo-9.11.4-26.P2.amzn2.13.17.aarch64

i686:
    bind-9.11.4-26.P2.amzn2.13.17.i686
    bind-pkcs11-9.11.4-26.P2.amzn2.13.17.i686
    bind-pkcs11-utils-9.11.4-26.P2.amzn2.13.17.i686
    bind-pkcs11-libs-9.11.4-26.P2.amzn2.13.17.i686
    bind-pkcs11-devel-9.11.4-26.P2.amzn2.13.17.i686
    bind-sdb-9.11.4-26.P2.amzn2.13.17.i686
    bind-libs-lite-9.11.4-26.P2.amzn2.13.17.i686
    bind-libs-9.11.4-26.P2.amzn2.13.17.i686
    bind-utils-9.11.4-26.P2.amzn2.13.17.i686
    bind-devel-9.11.4-26.P2.amzn2.13.17.i686
    bind-lite-devel-9.11.4-26.P2.amzn2.13.17.i686
    bind-chroot-9.11.4-26.P2.amzn2.13.17.i686
    bind-sdb-chroot-9.11.4-26.P2.amzn2.13.17.i686
    bind-export-libs-9.11.4-26.P2.amzn2.13.17.i686
    bind-export-devel-9.11.4-26.P2.amzn2.13.17.i686
    bind-debuginfo-9.11.4-26.P2.amzn2.13.17.i686

noarch:
    bind-license-9.11.4-26.P2.amzn2.13.17.noarch

src:
    bind-9.11.4-26.P2.amzn2.13.17.src

x86_64:
    bind-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-pkcs11-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-pkcs11-utils-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-pkcs11-libs-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-pkcs11-devel-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-sdb-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-libs-lite-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-libs-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-utils-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-devel-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-lite-devel-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-chroot-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-sdb-chroot-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-export-libs-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-export-devel-9.11.4-26.P2.amzn2.13.17.x86_64
    bind-debuginfo-9.11.4-26.P2.amzn2.13.17.x86_64

Additional References

Release Notes:  Amazon Linux 2 Release Notes

Red Hat: CVE-2026-10723, CVE-2026-11622, CVE-2026-11721, CVE-2026-13204, CVE-2026-13321

Mitre: CVE-2026-10723, CVE-2026-11622, CVE-2026-11721, CVE-2026-13204, CVE-2026-13321