CVE-2026-81642

critical

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 exe…

Vendor / product: Nlnetlabs — unbound

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

9.8

9.8 (CVSS v3.1)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity source: NVD CVSS v3.1 (nvd@nist.gov)

Timeline (UTC)

Published: 2026-09-16 09:17

Modified: 2026-09-22 18:59

NVD status: Analyzed

Last synced 1 day ago

Verified against the source API 2026-10-27 07:07 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

nlnetlabs / unbound <1.26.1

Weakness classification (CWE)

CWE-122

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

Mitigation & advisories

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

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

References

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

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 07:07 UTC · record ↗

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CVE-2026-81642

Affected products

Weakness classification (CWE)

Mitigation & advisories

References

Data sources

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