Unexpected exit in certain situations with NSEC and NSEC3 both present
Summary
| CVE | CVE-2026-13204 |
|---|---|
| State | PUBLISHED |
| Assigner | isc |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-22 15:16:52 UTC |
| Updated | 2026-07-22 20:33:11 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Problem Types: CWE-617 | CWE-617 CWE-617 Reachable Assertion
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | DECLARED | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | ISC | BIND 9 | affected 9.11.0 9.18.50 custom | Not specified |
| CNA | ISC | BIND 9 | affected 9.20.0 9.20.24 custom | Not specified |
| CNA | ISC | BIND 9 | affected 9.21.0 9.21.23 custom | Not specified |
| CNA | ISC | BIND 9 | affected 9.11.3-S1 9.18.50-S1 custom | Not specified |
| CNA | ISC | BIND 9 | affected 9.20.9-S1 9.20.24-S1 custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| kb.isc.org/docs/cve-2026-13204 | [email protected] | kb.isc.org | |
| downloads.isc.org/isc/bind9/9.21.24 | [email protected] | downloads.isc.org | |
| downloads.isc.org/isc/bind9/9.20.26 | [email protected] | downloads.isc.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: ISC would like to thank Qifan Zhang of Palo Alto Networks for bringing this vulnerability to our attention. (en)
Additional Advisory Data
Solutions
CNA: Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.26, 9.21.24, or 9.20.26-S1.
Workarounds
CNA: No workarounds known.
Exploits
CNA: We are not aware of any active exploits.
There are currently no legacy QID mappings associated with this CVE.