Vulnerability in Isc Bind 9

CVE-2026-81736

If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.

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

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-81736?
CVE-2026-81736 is a high-severity vulnerability in Isc Bind 9, classified under CWE-1050. CVSS score: 7.5/10. Published 2026-09-16.
How severe is CVE-2026-81736?
High severity. CVSS v3 base score is 7.5 out of 10.