CVE-2026-13321 (GCVE-0-2026-13321)
Vulnerability from cvelistv5 – Published: 2026-07-22 14:16 – Updated: 2026-07-22 18:51
VLAI
EPSS
VEX
Title
DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field
Summary
The BIND resolver accepts validly-signed NSEC records where the "Next Domain Name" field points outside the signer's zone.
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.
Severity
8.6 (High)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-22 18:51 UTC
CWE
- CWE-346 - Origin Validation Error
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://kb.isc.org/docs/cve-2026-13321 | vendor-advisory |
| https://downloads.isc.org/isc/bind9/9.20.26 | patch |
| https://downloads.isc.org/isc/bind9/9.21.24 | patch |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| ISC | BIND 9 |
Affected:
9.11.0 , ≤ 9.18.50
(custom)
Affected: 9.20.0 , ≤ 9.20.24 (custom) Affected: 9.21.0 , ≤ 9.21.23 (custom) Affected: 9.11.3-S1 , ≤ 9.18.50-S1 (custom) Affected: 9.20.9-S1 , ≤ 9.20.24-S1 (custom) cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:* cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:* cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:* cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:* cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:* |
Date Public
2026-07-22 00:00
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-13321",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-22T18:51:32.344539Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-07-22T18:51:47.414Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "BIND 9",
"vendor": "ISC",
"versions": [
{
"lessThanOrEqual": "9.18.50",
"status": "affected",
"version": "9.11.0",
"versionType": "custom"
},
{
"lessThanOrEqual": "9.20.24",
"status": "affected",
"version": "9.20.0",
"versionType": "custom"
},
{
"lessThanOrEqual": "9.21.23",
"status": "affected",
"version": "9.21.0",
"versionType": "custom"
},
{
"lessThanOrEqual": "9.18.50-S1",
"status": "affected",
"version": "9.11.3-S1",
"versionType": "custom"
},
{
"lessThanOrEqual": "9.20.24-S1",
"status": "affected",
"version": "9.20.9-S1",
"versionType": "custom"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
"versionEndIncluding": "9.18.50",
"versionStartIncluding": "9.11.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
"versionEndIncluding": "9.20.24",
"versionStartIncluding": "9.20.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
"versionEndIncluding": "9.21.23",
"versionStartIncluding": "9.21.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
"versionEndIncluding": "9.18.50-S1",
"versionStartIncluding": "9.11.3-S1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
"versionEndIncluding": "9.20.24-S1",
"versionStartIncluding": "9.20.9-S1",
"vulnerable": true
}
],
"operator": "OR"
}
]
}
],
"credits": [
{
"lang": "en",
"value": "ISC would like to thank Qifan Zhang of Palo Alto Networks for bringing this vulnerability to our attention."
}
],
"datePublic": "2026-07-22T00:00:00.000Z",
"descriptions": [
{
"lang": "en",
"value": "The BIND resolver accepts validly-signed NSEC records where the \"Next Domain Name\" field points outside the signer\u0027s zone.\nThis 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."
}
],
"exploits": [
{
"lang": "en",
"value": "We are not aware of any active exploits."
}
],
"impacts": [
{
"descriptions": [
{
"lang": "en",
"value": "An attacker controlling any DNSSEC-signed zone can craft NSEC records that span into victim zones, enabling cross-zone cache poisoning with authenticated denial-of-service responses (AD=1)."
}
]
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 8.6,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "CHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-346",
"description": "CWE-346 Origin Validation Error",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-07-22T14:16:10.450Z",
"orgId": "404fd4d2-a609-4245-b543-2c944a302a22",
"shortName": "isc"
},
"references": [
{
"name": "CVE-2026-13321",
"tags": [
"vendor-advisory"
],
"url": "https://kb.isc.org/docs/cve-2026-13321"
},
{
"tags": [
"patch"
],
"url": "https://downloads.isc.org/isc/bind9/9.20.26"
},
{
"tags": [
"patch"
],
"url": "https://downloads.isc.org/isc/bind9/9.21.24"
}
],
"solutions": [
{
"lang": "en",
"value": "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."
}
],
"source": {
"discovery": "EXTERNAL"
},
"title": "DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field",
"workarounds": [
{
"lang": "en",
"value": "No workarounds known."
}
],
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "404fd4d2-a609-4245-b543-2c944a302a22",
"assignerShortName": "isc",
"cveId": "CVE-2026-13321",
"datePublished": "2026-07-22T14:16:10.450Z",
"dateReserved": "2026-06-25T08:45:35.931Z",
"dateUpdated": "2026-07-22T18:51:47.414Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-13321",
"date": "2026-09-20",
"epss": "0.00223",
"percentile": "0.1321"
},
"microsoft_vex": {
"current_release_date": "2026-08-07T04:20:03.000Z",
"cve": "CVE-2026-13321",
"id": "msrc_CVE-2026-13321",
"initial_release_date": "2026-07-25T01:04:43.000Z",
"product_status:fixed": "1",
"product_status:known_affected": "1",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field",
"url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-13321.json",
"version": "2"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "BIND 9",
"vendor": "ISC",
"versions": [
{
"lessThanOrEqual": "9.18.50",
"status": "affected",
"version": "9.11.0",
"versionType": "custom"
},
{
"lessThanOrEqual": "9.20.24",
"status": "affected",
"version": "9.20.0",
"versionType": "custom"
},
{
"lessThanOrEqual": "9.21.23",
"status": "affected",
"version": "9.21.0",
"versionType": "custom"
},
{
"lessThanOrEqual": "9.18.50-S1",
"status": "affected",
"version": "9.11.3-S1",
"versionType": "custom"
},
{
"lessThanOrEqual": "9.20.24-S1",
"status": "affected",
"version": "9.20.9-S1",
"versionType": "custom"
}
]
}
],
"source": "security-officer@isc.org"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "The BIND resolver accepts validly-signed NSEC records where the \"Next Domain Name\" field points outside the signer\u0027s zone.\nThis 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."
}
],
"id": "CVE-2026-13321",
"lastModified": "2026-07-22T20:33:11.590",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 8.6,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "CHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 4.0,
"source": "security-officer@isc.org",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-13321",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-22T18:51:32.344539Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-07-22T15:16:52.200",
"references": [
{
"source": "security-officer@isc.org",
"url": "https://downloads.isc.org/isc/bind9/9.20.26"
},
{
"source": "security-officer@isc.org",
"url": "https://downloads.isc.org/isc/bind9/9.21.24"
},
{
"source": "security-officer@isc.org",
"url": "https://kb.isc.org/docs/cve-2026-13321"
}
],
"sourceIdentifier": "security-officer@isc.org",
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-346"
}
],
"source": "security-officer@isc.org",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Important",
"current_release_date": "2026-09-17T08:04:52+00:00",
"cve": "CVE-2026-13321",
"id": "CVE-2026-13321",
"initial_release_date": "2026-07-22T00:00:00+00:00",
"product_status:fixed": "562",
"product_status:known_affected": "8",
"product_status:known_not_affected": "141",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "bind: bind9: DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-13321.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-13321",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-22T18:51:32.344539Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-07-22T18:51:44.118Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "BIND 9",
"vendor": "ISC",
"versions": [
{
"lessThanOrEqual": "9.18.50",
"status": "affected",
"version": "9.11.0",
"versionType": "custom"
},
{
"lessThanOrEqual": "9.20.24",
"status": "affected",
"version": "9.20.0",
"versionType": "custom"
},
{
"lessThanOrEqual": "9.21.23",
"status": "affected",
"version": "9.21.0",
"versionType": "custom"
},
{
"lessThanOrEqual": "9.18.50-S1",
"status": "affected",
"version": "9.11.3-S1",
"versionType": "custom"
},
{
"lessThanOrEqual": "9.20.24-S1",
"status": "affected",
"version": "9.20.9-S1",
"versionType": "custom"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
"versionEndIncluding": "9.18.50",
"versionStartIncluding": "9.11.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
"versionEndIncluding": "9.20.24",
"versionStartIncluding": "9.20.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
"versionEndIncluding": "9.21.23",
"versionStartIncluding": "9.21.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
"versionEndIncluding": "9.18.50-S1",
"versionStartIncluding": "9.11.3-S1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
"versionEndIncluding": "9.20.24-S1",
"versionStartIncluding": "9.20.9-S1",
"vulnerable": true
}
],
"operator": "OR"
}
]
}
],
"credits": [
{
"lang": "en",
"value": "ISC would like to thank Qifan Zhang of Palo Alto Networks for bringing this vulnerability to our attention."
}
],
"datePublic": "2026-07-22T00:00:00.000Z",
"descriptions": [
{
"lang": "en",
"value": "The BIND resolver accepts validly-signed NSEC records where the \"Next Domain Name\" field points outside the signer\u0027s zone.\nThis 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."
}
],
"exploits": [
{
"lang": "en",
"value": "We are not aware of any active exploits."
}
],
"impacts": [
{
"descriptions": [
{
"lang": "en",
"value": "An attacker controlling any DNSSEC-signed zone can craft NSEC records that span into victim zones, enabling cross-zone cache poisoning with authenticated denial-of-service responses (AD=1)."
}
]
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 8.6,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "CHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-346",
"description": "CWE-346 Origin Validation Error",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-07-22T14:16:10.450Z",
"orgId": "404fd4d2-a609-4245-b543-2c944a302a22",
"shortName": "isc"
},
"references": [
{
"name": "CVE-2026-13321",
"tags": [
"vendor-advisory"
],
"url": "https://kb.isc.org/docs/cve-2026-13321"
},
{
"tags": [
"patch"
],
"url": "https://downloads.isc.org/isc/bind9/9.20.26"
},
{
"tags": [
"patch"
],
"url": "https://downloads.isc.org/isc/bind9/9.21.24"
}
],
"solutions": [
{
"lang": "en",
"value": "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."
}
],
"source": {
"discovery": "EXTERNAL"
},
"title": "DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field",
"workarounds": [
{
"lang": "en",
"value": "No workarounds known."
}
],
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "404fd4d2-a609-4245-b543-2c944a302a22",
"assignerShortName": "isc",
"cveId": "CVE-2026-13321",
"datePublished": "2026-07-22T14:16:10.450Z",
"dateReserved": "2026-06-25T08:45:35.931Z",
"dateUpdated": "2026-07-22T18:51:47.414Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…