# CVE-2026-13204: CVE-2026-13204

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

If a provably insecure domain is covered by both an NSEC and NSEC3 record at the parent, and there exist an RRSIG for only one of these types, then BIND may exit unexpectedly with an assertion while validating this proof.
This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- isc / bind: ≥ 9.11.0; ≤ 9.18.50 (affected, custom). Source: NVD
- isc / bind: ≥ 9.11.3; ≤ 9.18.50 (affected, custom). Source: NVD
- 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": "9.18.50",
            "versionStartIncluding": "9.11.0",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:*",
            "versionEndIncluding": "9.18.50",
            "versionStartIncluding": "9.11.3",
            "vulnerable": true
          },
          {
            "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-617

## 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-2026-13204 (security-officer@isc.org; Vendor Advisory)

## Provenance

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-13204; retrieved 2026-11-02; source updated 2026-11-02

Revision: 8afb69b4c470f12b2f6f16d458832257d660c07968ad738ff934ffa6ab149f66

Canonical: https://y2.dev/cve/CVE-2026-13204

## 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.