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.
CVE-2026-11331
Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-22. a secondary CVSS source baseline 7.5; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(high)
- EPSS
- —
- KEV
- Not listed
Published
July 22, 2026
Last Modified
July 22, 2026
Advisory Details (3)
Auto-updated Jul 22, 2026CVE-2026-11331: Potential wildcard CNAME RPZ policy bypass
https://kb.isc.org/docs/cve-2026-11331Vendor Advisories for CVE-2026-11331(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 8× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-22 21:59 UTCEG score recompute
- 2026-07-22 21:59 UTCGHSA enrichment
- 2026-07-22 19:05 UTCEG score recompute
- 2026-07-22 19:05 UTCGHSA enrichment
- 2026-07-22 17:10 UTCEG score recompute
- 2026-07-22 17:09 UTCGHSA enrichment
- 2026-07-22 14:48 UTCEG score recompute
- 2026-07-22 14:46 UTCMITRE cvelistV5first tracked
Frequently asked(4)
What is CVE-2026-11331?
When was CVE-2026-11331 disclosed?
What is the CVSS score of CVE-2026-11331?
How do I remediate CVE-2026-11331?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-11331
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