What is CVE-2026-11605?

CVE-2026-11605 is a high-severity vulnerability in Isc Bind 9, classified under CWE-408. CVSS score: 7.5/10. Published 2026-07-22.

How severe is CVE-2026-11605?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Isc Bind 9

CVE-2026-11605

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.

EPSS: 0.005 (43.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Isc Bind 9 — versions 9.20.0, 9.21.0, 9.20.9-S1

Weakness classification (CWE)

CWE-408

References

security-officer@isc.org (vendor-advisory)
security-officer@isc.org (patch)
security-officer@isc.org (patch)

Frequently asked questions

What is CVE-2026-11605?: CVE-2026-11605 is a high-severity vulnerability in Isc Bind 9, classified under CWE-408. CVSS score: 7.5/10. Published 2026-07-22.
How severe is CVE-2026-11605?: High severity. CVSS v3 base score is 7.5 out of 10.