CVE-2026-81642

critical · 9.1

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.

9.1

CVSS

1.0%

EPSS (exploit prob.)

62nd

EPSS percentile

2026-09-16

Published

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Red

Weaknesses

CWE-122

Affected products

Vendor	Product	Affected versions
nlnetlabs	unbound	< 1.26.1

Check a specific version with /api/v1/cve/match.

References

https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-81642.txt

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-81642