---
title: "CVE-2026-97313: BIND 9 - Denial of Service"
description: "BIND 9 versions 9.16.0 through 9.18.50, 9.20.0 through 9.20.29, 9.21.0 through 9.21.26, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.29-S1 contain a denial of service caused by assertion failure when processing recursive followed by non-recursive queries with specific RPZ zone configurations, letting attackers cause server crash, exploit requires recursive queries enabled and specific RPZ zones configured."
url: https://panop.io/threat-heartbeat/CVE-2026-97313/
---

# CVE-2026-97313 BIND 9 - Denial of Service

BIND 9 versions 9.16.0 through 9.18.50, 9.20.0 through 9.20.29, 9.21.0 through 9.21.26, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.29-S1 contain a denial of service caused by assertion failure when processing recursive followed by non-recursive queries with specific RPZ zone configurations, letting attackers cause server crash, exploit requires recursive queries enabled and specific RPZ zones configured.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

None known

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-97313)

## Details

Type

Denial of Service

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Published

21 October 2026

Updated

22 October 2026

Weakness

[CWE-617](https://cwe.mitre.org/data/definitions/617.html)

## Vendor fix

Update to a version later than 9.21.26 or the latest available version.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-97313](https://nvd.nist.gov/vuln/detail/CVE-2026-97313)
- [https://kb.isc.org/docs/cve-2026-97313](https://kb.isc.org/docs/cve-2026-97313)
- [https://downloads.isc.org/isc/bind9/9.20.30](https://downloads.isc.org/isc/bind9/9.20.30)
- [https://downloads.isc.org/isc/bind9/9.21.27](https://downloads.isc.org/isc/bind9/9.21.27)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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