CVE-2026-11622

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.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.5% chance of exploitation in the next 30 days; higher than 45% of CVEs (scores of 2026-10-25)

CWE

CWE-770

Published

2026-07-22

Modified

2026-10-24

Record from

the NVD, synced 2026-10-25

References

• https://downloads.isc.org/isc/bind9/9.20.26
• https://downloads.isc.org/isc/bind9/9.21.24
• https://kb.isc.org/docs/cve-2026-11622

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