CVE-2026-19668 Resource Exhaustion via Excessive DNSSEC Cryptographic Material Matching
Attackers can cause resource exhaustion in BIND recursive resolvers by sending specific invalid DNSSEC records, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-19668?
CVE-2026-19668 is a medium-severity denial of service vulnerability in ISC BIND 9, published on 16 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A BIND recursive resolver may experience excessive resource consumption if it encounters large numbers of a particular kind of invalid DNSSEC record. Default limits on "max-records-per-type" and "max-types-per-name" help mitigate the exposure. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
Weakness: CWE-407
Which versions are affected by CVE-2026-19668?
How do I fix CVE-2026-19668?
Apply the vendor's patch.
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-2026-19668 being exploited?
There is no known exploitation of CVE-2026-19668 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-19668, AZL-103338, BELL-CVE-2026-19668, DEBIAN-CVE-2026-19668, ECHO-dfd2-036e-f8e2, GHSA-qrrf-rhq5-mvxv and 4 more.