CVE-2026-81642

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.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-81642.txt	Mitigation Patch Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:nlnetlabs:unbound:*:*:*:*:*:*:*:*

History

22 Sep 2026, 18:59

Type	Values Removed	Values Added
CPE		cpe:2.3:a:nlnetlabs:unbound::::::::
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 9.8
First Time		Nlnetlabs Nlnetlabs unbound
References	~~() https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-81642.txt -~~	() https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-81642.txt - Mitigation, Patch, Vendor Advisory

Information

Published : 2026-09-16 09:17

Updated : 2026-09-22 18:59

NVD link : CVE-2026-81642

Mitre link : CVE-2026-81642

CVE.ORG link : CVE-2026-81642

JSON object : View

Products Affected

nlnetlabs

unbound

CWE

CWE-122

Heap-based Buffer Overflow

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