CVE-2026-11331Potential wildcard CNAME RPZ policy bypass
Updated under an hour ago ()
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It affects ISC BIND 9. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Weakness (CWE)
- CWE-790
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- isc
- NVD analysis
- Undergoing Analysis
- Record last updated
- Jul 22, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
ISC BIND 9 isc:bind_9 (from the name) | from 9.16.0 through 9.18.50; from 9.20.0 through 9.20.24; from 9.21.0 through 9.21.23; from 9.16.8-S1 through 9.18.50-S1; from 9.20.9-S1 through 9.20.24-S1 | CNA record |
References
- https://kb.isc.org/docs/cve-2026-11331vendor-advisory
- https://downloads.isc.org/isc/bind9/9.20.26patch
- https://downloads.isc.org/isc/bind9/9.21.24patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.