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.
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.
Advisories
No advisories yet.
Fixes
Solution
Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.26, 9.21.24, or 9.20.26-S1.
Workaround
No workarounds known.
References
History
Wed, 22 Jul 2026 15:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Potential memory usage beyond configured limits | |
| First Time appeared |
Isc
Isc bind |
|
| Weaknesses | CWE-770 | |
| CPEs | cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Isc
Isc bind |
|
| References |
| |
| Metrics |
cvssV3_1
|
Projects
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Status: PUBLISHED
Assigner: isc
Published:
Updated: 2026-07-22T18:53:14.635Z
Reserved: 2026-06-08T20:17:01.626Z
Link: CVE-2026-11622
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OpenCVE Enrichment
No data.
Weaknesses