CVE-2026-81736

high

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 C…

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

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: 2026-09-16 14:17

Modified: 2026-10-26 21:10

NVD status: Awaiting Analysis

Last synced 2 days ago

Verified against the source API 2026-10-27 06:54 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

Not reported by the source (unknown — not "none").

Weakness classification (CWE)

CWE-1050

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

Mitigation & advisories

No vendor advisory or patch reference tagged by NVD. Check the references below.

References

https://downloads.isc.org/isc/bind9/9.20.29 security-officer@isc.org
https://downloads.isc.org/isc/bind9/9.21.26 security-officer@isc.org
https://kb.isc.org/docs/cve-2026-81736 security-officer@isc.org

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 06:54 UTC · record ↗

Learn the basics

Understanding CVEs and CVSS Scores