CVE-2026-11622 Potential memory usage beyond configured limits

High 7.5 Published Updated

Attackers can cause excessive memory usage in BIND DNSSEC resolvers via random subdomain attacks, 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-2026-11622?

CVE-2026-11622 is a high-severity denial of service vulnerability in ISC BIND 9, published on 22 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-770

Which versions are affected by CVE-2026-11622?

How do I fix CVE-2026-11622?

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-2026-11622 being exploited?

There is no known exploitation of CVE-2026-11622 in the wild and no public exploit code.

Sources

Also known as ALPINE-CVE-2026-11622, AZL-93135, BELL-CVE-2026-11622, CLSA-2026-1785562289, CLSA-2026-1785835455, CLSA-2026-1785845701 and 12 more.

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