CVE-2026-81642
Publication date 16 September 2026
Last updated 6 October 2026
Ubuntu priority
Description
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| unbound | 26.04 LTS resolute |
Fixed 1.24.2-1ubuntu2.3
|
| 24.04 LTS noble |
Fixed 1.19.2-1ubuntu3.10
|
|
| 22.04 LTS jammy |
Fixed 1.13.1-1ubuntu5.16
|
|
| 20.04 LTS focal |
Fixed 1.9.4-2ubuntu1.11+esm2
|
|
| 18.04 LTS bionic |
Fixed 1.6.7-1ubuntu2.6+esm5
|
|
| 16.04 LTS xenial |
Fixed 1.5.8-1ubuntu1.1+esm4
|
|
| 14.04 LTS trusty |
Fixed 1.4.22-1ubuntu4.14.04.3+esm4
|
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| Package | Patch details |
|---|---|
| unbound |
Severity score breakdown
CVSS version:
Base score
9.1 · Critical
Vector: 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
Base score
9.8 · Critical
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
Related Ubuntu Security Notices (USN)
- USN-8873-1
- Unbound vulnerabilities
- 6 October 2026