CVE-2026-11622

high

A DNSSEC validating resolver that is under a random subdomain attack against a DNSSEC-signed zone can suffer from runaway memory usage.

Vendor / product: Isc — bind

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

7.5

7.5 (CVSS v3.1)

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

Severity source: NVD CVSS v3.1 (security-officer@isc.org)

Timeline (UTC)

Published: 2026-07-22 15:16

Modified: 2026-11-02 17:42

NVD status: Analyzed

Last synced 1 day ago

Verified against the source API 2026-11-03 07:34 UTC

Exploitation

Not listed in CISA KEV (as of last catalog sync)

Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

isc / bind ≥9.11.3 ≤9.18.50, ≥9.18.0 ≤9.18.50, ≥9.20.0 ≤9.20.24, ≥9.20.9 ≤9.20.24, ≥9.21.0 ≤9.21.23

Weakness classification (CWE)

CWE-770

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://kb.isc.org/docs/cve-2026-11622

References

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

Data sources

NVD CVE API 2.0 — fetched 2026-11-03 07:34 UTC · record ↗

Learn the basics

Understanding CVEs and CVSS Scores

CVE-2026-11622

Affected products

Weakness classification (CWE)

Mitigation & advisories

References

Data sources

Learn the basics

Related CVEs