The issue is a resource exhaustion vulnerability associated with DNSSEC validation. BIND always validates all RRSIG records in an answer, even if they are not strictly needed. A query to an authoritative server/zone which returns many valid but superfluous RRSIG records causes the validator to waste disproportionate CPU time. This issue affects BIND 9 versions 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, and 9.20.9-S1 through 9.20.24-S1.
CVSS Details
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade bind | Jul 28, 2026 | Jul 22, 2026 |
| Debian | — | Upgrade bind9 | Jul 28, 2026 | Jul 28, 2026 |
| Redhat_linux | — | — | Jul 27, 2026 | Jul 22, 2026 |
| Ubuntu | — | Upgrade bind9 | Aug 19, 2026 | Aug 19, 2026 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Aug 17, 2026 | Jul 22, 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