# CVE-2026-11605: CVE-2026-11605

Status: published. Published: 2026-07-22. Updated: 2026-11-02.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- isc / bind: ≥ 9.20.0; ≤ 9.20.24 (affected, custom). Source: NVD
- isc / bind: ≥ 9.20.9; ≤ 9.20.24 (affected, custom). Source: NVD
- isc / bind: ≥ 9.21.0; ≤ 9.21.23 (affected, custom). Source: NVD

## NVD configuration conditions

Affected CPE matches depend on the following AND/OR and negation conditions:

```json
[
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
            "versionEndIncluding": "9.20.24",
            "versionStartIncluding": "9.20.0",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:*",
            "versionEndIncluding": "9.20.24",
            "versionStartIncluding": "9.20.9",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
            "versionEndIncluding": "9.21.23",
            "versionStartIncluding": "9.21.0",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  }
]
```

## Severity and prioritization

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H; source: NVD: security-officer@isc.org

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable yes; technical impact partial; source NVD SSVC: 134c704f-9b21-4f2e-91b3-4a467353bcc0

- Weaknesses: CWE-408

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://downloads.isc.org/isc/bind9/9.20.26 (security-officer@isc.org; Product)

- https://downloads.isc.org/isc/bind9/9.21.24 (security-officer@isc.org; Product)

- https://kb.isc.org/docs/cve-2026-11605 (security-officer@isc.org; Vendor Advisory)

## Provenance

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11605; retrieved 2026-11-02; source updated 2026-11-02

Revision: 5a2e56e2e6abd5d5f5d2083b9dc81ee3017283178af0f36b90026fa700e7a95c

Canonical: https://y2.dev/cve/CVE-2026-11605

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.