CVE-2026-42396 Insufficient Validation of Member Zone Data May Cause Catalog Zone Transfer to Fail

Medium 4.9 Published 21 May 2026 Updated 21 May 2026

Attackers can cause catalog zone transfer failures in PowerDNS Authoritative by exploiting insufficient validation of member zone data.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-42396?

CVE-2026-42396 is a medium-severity code injection vulnerability in PowerDNS Authoritative, published on 21 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.

Official description

Insufficient Validation of Member Zone Data May Cause Catalog Zone Transfer to Fail

Weakness: CWE-94

Which versions are affected by CVE-2026-42396?

It affects 1 product.

Products include Powerdns Authoritative.

How do I fix CVE-2026-42396?

Apply the vendor's patch.

Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.

Is CVE-2026-42396 being exploited?

There is no known exploitation of CVE-2026-42396 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2026-42396, GHSA-hm6h-mcgv-h2x8, UBUNTU-CVE-2026-42396.