CVE-2026-40719 Denial of service in MaraDNS
Attackers can exhaust connection slots in MaraDNS by configuring a zone with an unresolvable authoritative nameserver address.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-40719?
CVE-2026-40719 is a high-severity denial of service vulnerability in MaraDNS, published on 15 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Deadwood in MaraDNS 3.5.0036 allows attackers to exhaust connection slots via a zone whose authoritative nameserver address cannot be resolved.
Weakness: CWE-670
Which versions are affected by CVE-2026-40719?
How do I fix CVE-2026-40719?
No fix has been published for CVE-2026-40719 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-40719 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40719 exists.
Sources
Also known as DEBIAN-CVE-2026-40719, GHSA-8wr7-69hr-44pw, GHSA-cfc6-vhrv-62cj, UBUNTU-CVE-2026-40719.