CVE-2026-81642CWE-122

CVE-2026-81642

Critical · published September 16, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
61.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
9.1 · 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/U:Red
EPSS
0.00962 · 61.3th percentile
Weakness
CWE-122 · Heap-based Buffer Overflow
Published
2026-09-16T13:17Z
Affected products (1)
ProductVersionsFixed in
nlnetlabs/unbound< 1.26.11.26.1
References (1)
https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-81642.txt · [email protected]
EPSS history
Timeline
  • 17 SEP 03:32Z
    EPSS moved — → 1%
    epss
  • 16 SEP 08:30Z
    Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY
    cvelistv5