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 Details
- CVSS 4.0 Base Score: 9.1 (CRITICAL)
- CVSS 4.0 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/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)
- CVSS 3.1 Base Score: 9.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade unbound-develUpgrade python3-unboundUpgrade unbound-dracutUpgrade unboundUpgrade unbound-libs | Oct 11, 2026 | Sep 23, 2026 |
| Alpine Linux | — | Upgrade unbound | Sep 21, 2026 | Sep 16, 2026 |
| Amazon_linux_2023 | — | Upgrade unbound-debuginfoUpgrade unbound-debugsourceUpgrade unbound-develUpgrade unbound-anchor-debuginfoUpgrade python3-unbound-debuginfoUpgrade unbound-libsUpgrade unboundUpgrade unbound-utilsUpgrade unbound-utils-debuginfoUpgrade python3-unboundUpgrade unbound-libs-debuginfoUpgrade unbound-anchor | Sep 30, 2026 | Sep 16, 2026 |
| Debian | — | Upgrade unbound | Sep 21, 2026 | Sep 16, 2026 |
| Freebsd | — | Upgrade unbound | Sep 18, 2026 | Sep 16, 2026 |
| Redhat_linux | — | Upgrade unbound-debugsourceUpgrade python3-unbound-debuginfoUpgrade unbound-debuginfoUpgrade unbound-utils-debuginfoUpgrade unbound-anchor-debuginfoUpgrade unbound-dracutUpgrade unbound-pythonUpgrade unboundUpgrade unbound-libsNo solution existsUpgrade unbound-libs-debuginfoUpgrade python3-unboundUpgrade unbound-utilsUpgrade unbound-develUpgrade unbound-anchor | Sep 21, 2026 | Sep 16, 2026 |
| Rocky_linux | — | Upgrade unbound-libs-debuginfoUpgrade unbound-debuginfoUpgrade python3-unboundUpgrade unbound-develUpgrade python3-unbound-debuginfoUpgrade unbound-libsUpgrade unbound-utilsUpgrade unbound-anchor-debuginfoUpgrade unbound-anchorUpgrade unbound-debugsourceUpgrade unbound-dracutUpgrade unboundUpgrade unbound-utils-debuginfo | Sep 28, 2026 | Sep 25, 2026 |
| Ubuntu | — | Upgrade unbound (Ubuntu Pro)Upgrade unboundUpgrade python-unbound (Ubuntu Pro)Upgrade libunbound2 (Ubuntu Pro)Upgrade libunbound8Upgrade python3-unboundUpgrade libunbound8 (Ubuntu Pro)Upgrade python3-unbound (Ubuntu Pro) | Oct 6, 2026 | Oct 6, 2026 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Sep 28, 2026 | Sep 16, 2026 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub