# CVE-2026-11331

## Summary

- **CVE ID:** CVE-2026-11331
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)
- **CWE:** CWE-790
- **Published:** Jul 22, 2026
- **Last Modified:** Jul 24, 2026

## Description

An attacker who knows (or guesses) that a resolver uses RPZ with wildcard CNAME policies can craft query names long enough to trigger a NAMETOOLONG error condition during RPZ processing. This is not handled correctly and may lead to defeating the RPZ rule. It also may lead to an unexpected exit of the BIND 9 software.
This issue affects BIND 9 versions 9.16.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.16.8-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.

## Affected Products

- ISC — BIND 9 (9.16.0)
- ISC — BIND 9 (9.20.0)
- ISC — BIND 9 (9.21.0)
- ISC — BIND 9 (9.16.8-S1)
- ISC — BIND 9 (9.20.9-S1)

## References

- [CNA](https://kb.isc.org/docs/cve-2026-11331)
- [CNA](https://downloads.isc.org/isc/bind9/9.20.26)
- [CNA](https://downloads.isc.org/isc/bind9/9.21.24)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.43%
- **EPSS Percentile:** 35.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._