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Ubuntu Security Notice USN-8124-1
March 25, 2026

bind9 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 25.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS

Summary:

Several security issues were fixed in Bind.

Software Description:
- bind9: Internet Domain Name Server

Details:

Samy Medjahed discovered that Bind incorrectly handled insecure
delegation validation. A remote attacker could possibly use this issue to
cause excessive NSEC3 iterations, consuming CPU resources, and leading to a
denial of service. (CVE-2026-1519)

Vitaly Simonovich discovered that Bind incorrectly handled memory when
preparing DNSSEC proofs of non-existence. A remote attacker could possibly
use this issue to cause memory consumption, leading to a denial of service.
This issue only affected Ubuntu 25.10. (CVE-2026-3104)

Vitaly Simonovich discovered that Bind incorrectly handled authenticated
queries containing TKEY records. A remote attacker could possibly use this
issue to cause Bind to crash, resulting in a denial of service. This issue
only affected Ubuntu 25.10. (CVE-2026-3119)

It was discovered that Bind incorrectly handled DNS queries signed with
SIG(0). A remote attacker could possibly use this issue to bypass ACLs.
This issue only affected Ubuntu 25.10. (CVE-2026-3591)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 25.10
  bind9                           1:9.20.11-1ubuntu2.2

Ubuntu 24.04 LTS
  bind9                           1:9.18.39-0ubuntu0.24.04.3

Ubuntu 22.04 LTS
  bind9                           1:9.18.39-0ubuntu0.22.04.3

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-8124-1
  CVE-2026-1519, CVE-2026-3104, CVE-2026-3119, CVE-2026-3591

Package Information:
  https://launchpad.net/ubuntu/+source/bind9/1:9.20.11-1ubuntu2.2
  https://launchpad.net/ubuntu/+source/bind9/1:9.18.39-0ubuntu0.24.04.3
  https://launchpad.net/ubuntu/+source/bind9/1:9.18.39-0ubuntu0.22.04.3