CVE-2026-20038 (GCVE-0-2026-20038)
Vulnerability from cvelistv5
Published
2026-10-07 16:11
Modified
2026-10-07 18:05
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-284 - Improper Access Control
Summary
A vulnerability in the endpoint group (EPG) contract functionality of Cisco Nexus 9000 Series Fabric Switches in ACI Mode could allow an unauthenticated, remote attacker to bypass configured EPG contracts.
This vulnerability is due to an improper control with EPG contracts. An attacker could exploit this vulnerability by sending IPv4 or IPv6 packets using UDP source and destination ports that are assigned to DHCP traffic through an affected device. A successful exploit could allow the attacker to bypass EPG contracts on the affected device.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Cisco | Cisco NX-OS System Software in ACI Mode |
Version: 15.2(1g) Version: 15.2(2e) Version: 15.2(2f) Version: 15.2(2g) Version: 15.2(2h) Version: 15.2(3f) Version: 15.2(3e) Version: 15.2(3g) Version: 15.2(4d) Version: 15.2(4e) Version: 15.2(5c) Version: 15.2(5d) Version: 16.0(1g) Version: 15.2(5e) Version: 15.2(4f) Version: 15.2(6e) Version: 15.2(6h) Version: 16.0(1j) Version: 15.2(6g) Version: 15.2(7f) Version: 15.2(7g) Version: 16.0(2h) Version: 15.2(8d) Version: 16.0(2j) Version: 15.2(8e) Version: 16.0(3d) Version: 16.0(3e) Version: 15.2(8f) Version: 15.2(8g) Version: 15.3(1d) Version: 15.2(8h) Version: 16.0(4c) Version: 15.3(2a) Version: 15.2(8i) Version: 16.0(5h) Version: 15.3(2b) Version: 16.0(3g) Version: 16.0(5j) Version: 15.3(2c) Version: 16.0(6c) Version: 15.3(2d) Version: 16.1(1f) Version: 16.0(7e) Version: 16.0(8e) Version: 15.3(2e) Version: 16.0(8f) Version: 16.1(2f) Version: 16.1(2g) Version: 15.3(2f) Version: 16.0(9c) Version: 16.1(3f) Version: 16.0(9d) Version: 16.0(6h) Version: 16.0(8h) Version: 16.1(3g) Version: 16.0(9e) Version: 16.1(4h) Version: 16.1(5e) Version: 16.2(1g) Version: 16.0(9f) Version: 16.2(2e) |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-20038",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-07T18:02:43.242313Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-10-07T18:05:53.253Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unknown",
"product": "Cisco NX-OS System Software in ACI Mode",
"vendor": "Cisco",
"versions": [
{
"status": "affected",
"version": "15.2(1g)"
},
{
"status": "affected",
"version": "15.2(2e)"
},
{
"status": "affected",
"version": "15.2(2f)"
},
{
"status": "affected",
"version": "15.2(2g)"
},
{
"status": "affected",
"version": "15.2(2h)"
},
{
"status": "affected",
"version": "15.2(3f)"
},
{
"status": "affected",
"version": "15.2(3e)"
},
{
"status": "affected",
"version": "15.2(3g)"
},
{
"status": "affected",
"version": "15.2(4d)"
},
{
"status": "affected",
"version": "15.2(4e)"
},
{
"status": "affected",
"version": "15.2(5c)"
},
{
"status": "affected",
"version": "15.2(5d)"
},
{
"status": "affected",
"version": "16.0(1g)"
},
{
"status": "affected",
"version": "15.2(5e)"
},
{
"status": "affected",
"version": "15.2(4f)"
},
{
"status": "affected",
"version": "15.2(6e)"
},
{
"status": "affected",
"version": "15.2(6h)"
},
{
"status": "affected",
"version": "16.0(1j)"
},
{
"status": "affected",
"version": "15.2(6g)"
},
{
"status": "affected",
"version": "15.2(7f)"
},
{
"status": "affected",
"version": "15.2(7g)"
},
{
"status": "affected",
"version": "16.0(2h)"
},
{
"status": "affected",
"version": "15.2(8d)"
},
{
"status": "affected",
"version": "16.0(2j)"
},
{
"status": "affected",
"version": "15.2(8e)"
},
{
"status": "affected",
"version": "16.0(3d)"
},
{
"status": "affected",
"version": "16.0(3e)"
},
{
"status": "affected",
"version": "15.2(8f)"
},
{
"status": "affected",
"version": "15.2(8g)"
},
{
"status": "affected",
"version": "15.3(1d)"
},
{
"status": "affected",
"version": "15.2(8h)"
},
{
"status": "affected",
"version": "16.0(4c)"
},
{
"status": "affected",
"version": "15.3(2a)"
},
{
"status": "affected",
"version": "15.2(8i)"
},
{
"status": "affected",
"version": "16.0(5h)"
},
{
"status": "affected",
"version": "15.3(2b)"
},
{
"status": "affected",
"version": "16.0(3g)"
},
{
"status": "affected",
"version": "16.0(5j)"
},
{
"status": "affected",
"version": "15.3(2c)"
},
{
"status": "affected",
"version": "16.0(6c)"
},
{
"status": "affected",
"version": "15.3(2d)"
},
{
"status": "affected",
"version": "16.1(1f)"
},
{
"status": "affected",
"version": "16.0(7e)"
},
{
"status": "affected",
"version": "16.0(8e)"
},
{
"status": "affected",
"version": "15.3(2e)"
},
{
"status": "affected",
"version": "16.0(8f)"
},
{
"status": "affected",
"version": "16.1(2f)"
},
{
"status": "affected",
"version": "16.1(2g)"
},
{
"status": "affected",
"version": "15.3(2f)"
},
{
"status": "affected",
"version": "16.0(9c)"
},
{
"status": "affected",
"version": "16.1(3f)"
},
{
"status": "affected",
"version": "16.0(9d)"
},
{
"status": "affected",
"version": "16.0(6h)"
},
{
"status": "affected",
"version": "16.0(8h)"
},
{
"status": "affected",
"version": "16.1(3g)"
},
{
"status": "affected",
"version": "16.0(9e)"
},
{
"status": "affected",
"version": "16.1(4h)"
},
{
"status": "affected",
"version": "16.1(5e)"
},
{
"status": "affected",
"version": "16.2(1g)"
},
{
"status": "affected",
"version": "16.0(9f)"
},
{
"status": "affected",
"version": "16.2(2e)"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "A vulnerability in the endpoint group (EPG) contract functionality of Cisco Nexus 9000 Series Fabric Switches in ACI Mode could allow an unauthenticated, remote attacker to bypass configured EPG contracts.\r\n\r\nThis vulnerability is due to an improper control with EPG contracts. An attacker could exploit this vulnerability by sending IPv4 or IPv6 packets using UDP source and destination ports that are assigned to\u0026nbsp;DHCP traffic through an affected device. A successful exploit could allow the attacker to bypass EPG contracts on the affected device."
}
],
"exploits": [
{
"lang": "en",
"value": "The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 5.8,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "LOW",
"privilegesRequired": "NONE",
"scope": "CHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
"version": "3.1"
},
"format": "cvssV3_1"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-284",
"description": "Improper Access Control",
"lang": "en",
"type": "cwe"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-07T16:11:55.078Z",
"orgId": "d1c1063e-7a18-46af-9102-31f8928bc633",
"shortName": "cisco"
},
"references": [
{
"name": "cisco-sa-aci-epgcbp-SfDU7NLf",
"url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aci-epgcbp-SfDU7NLf"
}
],
"source": {
"advisory": "cisco-sa-aci-epgcbp-SfDU7NLf",
"defects": [
"CSCwr18270"
],
"discovery": "EXTERNAL"
},
"title": "Cisco Nexus 9000 Series Fabric Switches in ACI Mode Policy-Based Redirect Endpoint Group Contract Bypass Vulnerability"
}
},
"cveMetadata": {
"assignerOrgId": "d1c1063e-7a18-46af-9102-31f8928bc633",
"assignerShortName": "cisco",
"cveId": "CVE-2026-20038",
"datePublished": "2026-10-07T16:11:55.078Z",
"dateReserved": "2025-10-08T11:59:15.354Z",
"dateUpdated": "2026-10-07T18:05:53.253Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-20038\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-10-07T18:02:43.242313Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-10-07T18:02:43.964Z\"}}], \"cna\": {\"title\": \"Cisco Nexus 9000 Series Fabric Switches in ACI Mode Policy-Based Redirect Endpoint Group Contract Bypass Vulnerability\", \"source\": {\"defects\": [\"CSCwr18270\"], \"advisory\": \"cisco-sa-aci-epgcbp-SfDU7NLf\", \"discovery\": \"EXTERNAL\"}, \"metrics\": [{\"format\": \"cvssV3_1\", \"cvssV3_1\": {\"scope\": \"CHANGED\", \"version\": \"3.1\", \"baseScore\": 5.8, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}], \"affected\": [{\"vendor\": \"Cisco\", \"product\": \"Cisco NX-OS System Software in ACI Mode\", \"versions\": [{\"status\": \"affected\", \"version\": \"15.2(1g)\"}, {\"status\": \"affected\", \"version\": \"15.2(2e)\"}, {\"status\": \"affected\", \"version\": \"15.2(2f)\"}, {\"status\": \"affected\", \"version\": \"15.2(2g)\"}, {\"status\": \"affected\", \"version\": \"15.2(2h)\"}, {\"status\": \"affected\", \"version\": \"15.2(3f)\"}, {\"status\": \"affected\", \"version\": \"15.2(3e)\"}, {\"status\": \"affected\", \"version\": \"15.2(3g)\"}, {\"status\": \"affected\", \"version\": \"15.2(4d)\"}, {\"status\": \"affected\", \"version\": \"15.2(4e)\"}, {\"status\": \"affected\", \"version\": \"15.2(5c)\"}, {\"status\": \"affected\", \"version\": \"15.2(5d)\"}, {\"status\": \"affected\", \"version\": \"16.0(1g)\"}, {\"status\": \"affected\", \"version\": \"15.2(5e)\"}, {\"status\": \"affected\", \"version\": \"15.2(4f)\"}, {\"status\": \"affected\", \"version\": \"15.2(6e)\"}, {\"status\": \"affected\", \"version\": \"15.2(6h)\"}, {\"status\": \"affected\", \"version\": \"16.0(1j)\"}, {\"status\": \"affected\", \"version\": \"15.2(6g)\"}, {\"status\": \"affected\", \"version\": \"15.2(7f)\"}, {\"status\": \"affected\", \"version\": \"15.2(7g)\"}, {\"status\": \"affected\", \"version\": \"16.0(2h)\"}, {\"status\": \"affected\", \"version\": \"15.2(8d)\"}, {\"status\": \"affected\", \"version\": \"16.0(2j)\"}, {\"status\": \"affected\", \"version\": \"15.2(8e)\"}, {\"status\": \"affected\", \"version\": \"16.0(3d)\"}, {\"status\": \"affected\", \"version\": \"16.0(3e)\"}, {\"status\": \"affected\", \"version\": \"15.2(8f)\"}, {\"status\": \"affected\", \"version\": \"15.2(8g)\"}, {\"status\": \"affected\", \"version\": \"15.3(1d)\"}, {\"status\": \"affected\", \"version\": \"15.2(8h)\"}, {\"status\": \"affected\", \"version\": \"16.0(4c)\"}, {\"status\": \"affected\", \"version\": \"15.3(2a)\"}, {\"status\": \"affected\", \"version\": \"15.2(8i)\"}, {\"status\": \"affected\", \"version\": \"16.0(5h)\"}, {\"status\": \"affected\", \"version\": \"15.3(2b)\"}, {\"status\": \"affected\", \"version\": \"16.0(3g)\"}, {\"status\": \"affected\", \"version\": \"16.0(5j)\"}, {\"status\": \"affected\", \"version\": \"15.3(2c)\"}, {\"status\": \"affected\", \"version\": \"16.0(6c)\"}, {\"status\": \"affected\", \"version\": \"15.3(2d)\"}, {\"status\": \"affected\", \"version\": \"16.1(1f)\"}, {\"status\": \"affected\", \"version\": \"16.0(7e)\"}, {\"status\": \"affected\", \"version\": \"16.0(8e)\"}, {\"status\": \"affected\", \"version\": \"15.3(2e)\"}, {\"status\": \"affected\", \"version\": \"16.0(8f)\"}, {\"status\": \"affected\", \"version\": \"16.1(2f)\"}, {\"status\": \"affected\", \"version\": \"16.1(2g)\"}, {\"status\": \"affected\", \"version\": \"15.3(2f)\"}, {\"status\": \"affected\", \"version\": \"16.0(9c)\"}, {\"status\": \"affected\", \"version\": \"16.1(3f)\"}, {\"status\": \"affected\", \"version\": \"16.0(9d)\"}, {\"status\": \"affected\", \"version\": \"16.0(6h)\"}, {\"status\": \"affected\", \"version\": \"16.0(8h)\"}, {\"status\": \"affected\", \"version\": \"16.1(3g)\"}, {\"status\": \"affected\", \"version\": \"16.0(9e)\"}, {\"status\": \"affected\", \"version\": \"16.1(4h)\"}, {\"status\": \"affected\", \"version\": \"16.1(5e)\"}, {\"status\": \"affected\", \"version\": \"16.2(1g)\"}, {\"status\": \"affected\", \"version\": \"16.0(9f)\"}, {\"status\": \"affected\", \"version\": \"16.2(2e)\"}], \"defaultStatus\": \"unknown\"}], \"exploits\": [{\"lang\": \"en\", \"value\": \"The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.\"}], \"references\": [{\"url\": \"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aci-epgcbp-SfDU7NLf\", \"name\": \"cisco-sa-aci-epgcbp-SfDU7NLf\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"A vulnerability in the endpoint group (EPG) contract functionality of Cisco Nexus 9000 Series Fabric Switches in ACI Mode could allow an unauthenticated, remote attacker to bypass configured EPG contracts.\\r\\n\\r\\nThis vulnerability is due to an improper control with EPG contracts. An attacker could exploit this vulnerability by sending IPv4 or IPv6 packets using UDP source and destination ports that are assigned to\u0026nbsp;DHCP traffic through an affected device. A successful exploit could allow the attacker to bypass EPG contracts on the affected device.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"cwe\", \"cweId\": \"CWE-284\", \"description\": \"Improper Access Control\"}]}], \"providerMetadata\": {\"orgId\": \"d1c1063e-7a18-46af-9102-31f8928bc633\", \"shortName\": \"cisco\", \"dateUpdated\": \"2026-10-07T16:11:55.078Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-20038\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-10-07T18:05:53.253Z\", \"dateReserved\": \"2025-10-08T11:59:15.354Z\", \"assignerOrgId\": \"d1c1063e-7a18-46af-9102-31f8928bc633\", \"datePublished\": \"2026-10-07T16:11:55.078Z\", \"assignerShortName\": \"cisco\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…