# CVE-2026-11605: Unnecessary validation of DNSSEC signed records

CVE-2026-11605 is fixed in 6 products on 1 platform, first by bind9 1:9.20.24-1ubuntu0.2, released July 22, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-11605
- Priority: High
- CVSS: 7.5 (Moderate)
- EPSS: 0.0067
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 22, 2026
- Weakness: Incorrect Behavior Order: Early Amplification
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-11605

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | bind opensuse-leap 16.0 | 9.20.26-160000.1.1 | [OPENSUSE-SU-2026:21489-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21489-1.md) | Jul 30, 2026 |
| Linux | bind sles 15.7 | 9.20.26-150700.3.29.1 | [SUSE-SU-2026:3426-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3426-1.md) | Jul 30, 2026 |
| Linux | bind9 Debian 12.15 (bookworm) | 1:9.18.49-1~deb12u2 | [DEBIAN-CVE-2026-11605](https://patchblox.com/security/data/fix/linux/debian-cve-2026-11605.md) | Jul 23, 2026 |
| Linux | bind9 Debian 13.5 (trixie) | 1:9.20.26-1~deb13u1 | [DEBIAN-CVE-2026-11605](https://patchblox.com/security/data/fix/linux/debian-cve-2026-11605.md) | Jul 23, 2026 |
| Linux | bind9 Debian 14 | 1:9.20.26-1 | [DEBIAN-CVE-2026-11605](https://patchblox.com/security/data/fix/linux/debian-cve-2026-11605.md) | Jul 23, 2026 |
| Linux | bind9 Ubuntu 26.04.1 LTS (resolute) | 1:9.20.24-1ubuntu0.2 | [bind9 1:9.20.24-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-bind9-1-9.20.24-1ubuntu0.2.md) | Jul 22, 2026 |
| Linux | bind9-dnsutils Ubuntu 26.04.1 LTS (resolute) | 1:9.20.24-1ubuntu0.2 | [bind9-dnsutils 1:9.20.24-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-bind9-dnsutils-1-9.20.24-1ubuntu0.2.md) | Jul 22, 2026 |
| Linux | bind9-host Ubuntu 26.04.1 LTS (resolute) | 1:9.20.24-1ubuntu0.2 | [bind9-host 1:9.20.24-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-bind9-host-1-9.20.24-1ubuntu0.2.md) | Jul 22, 2026 |
| Linux | bind9-libs Ubuntu 26.04.1 LTS (resolute) | 1:9.20.24-1ubuntu0.2 | [bind9-libs 1:9.20.24-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-bind9-libs-1-9.20.24-1ubuntu0.2.md) | Jul 22, 2026 |
| Linux | bind9-utils Ubuntu 26.04.1 LTS (resolute) | 1:9.20.24-1ubuntu0.2 | [bind9-utils 1:9.20.24-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-bind9-utils-1-9.20.24-1ubuntu0.2.md) | Jul 22, 2026 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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