CVE-2026-81642NVD

Vulnerability Summary

In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code execution as a result of digesting DNSKEYs. A DNSKEY with an owner compression pointer to its own RDATA can overflow the digest buffer. Remote code execution is possible through attacker controlled data. An adversary can exploit the vulnerability by controlling a malicious zone and querying a vulnerable Unbound.

Severity Level

UNKNOWN

Published Date

Sep 16, 2026

Last Modified

Sep 16, 2026

Exploitation Status

No confirmed exploitation yet

EPSS Score (30-Day)

0.96%Probability

Root Weakness (CWE)

CWE-122: Unknown/Unlisted Weakness ↗

Refer to the official MITRE database for detailed architectural specifications regarding this weakness.

CVSS v4.0 Base Metrics — Score 9.1 (CRITICAL)

Attack VectorNetwork

Attack ComplexityLow

Attack RequirementsNone

Privileges RequiredNone

User InteractionNone

Confidentiality (Vulnerable System)High

Integrity (Vulnerable System)High

Availability (Vulnerable System)High

Confidentiality (Subsequent System)High

Integrity (Subsequent System)High

Availability (Subsequent System)High

Affected & Patched Versions

Affected Versions

NLnet Labs Unbound < 1.26.1

Patched Versions

NLnet Labs Unbound 1.26.1

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