CVE-2026-11605

High

Description

The issue is a resource exhaustion vulnerability associated with DNSSEC validation. BIND always validates all RRSIG records in an answer, even if they are not strictly needed. A query to an authoritative server/zone which returns many valid but superfluous RRSIG records causes the validator to waste disproportionate CPU time. This issue affects BIND 9 versions 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, and 9.20.9-S1 through 9.20.24-S1.

SeverityHigh

CVSS7.5

Exploit probability—

ProductIsc Bind

PublishedJul 22, 2026

First seenJul 22, 2026

Weakness typeCWE-408CWE-408

How to fix

Patches

Vendor advisories

kb.isc.org/docs/cve-2026-11605

Affected products

Product	Affected versions	Fixed in
isc bind	9.20.0 ≤ v ≤ 9.20.24, 9.20.9 ≤ v ≤ 9.20.24, 9.21.0 ≤ v ≤ 9.21.23	—

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