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GHSA-8R87-MJ76-XW8H

Vulnerability from github – Published: 2026-10-07 18:32 – Updated: 2026-10-07 18:32

Details

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.

Severity

5.8 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-20038"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-284"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-07T17:16:54Z",
    "severity": "MODERATE"
  },
  "details": "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.\n\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.",
  "id": "GHSA-8r87-mj76-xw8h",
  "modified": "2026-10-07T18:32:10Z",
  "published": "2026-10-07T18:32:10Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-20038"
    },
    {
      "type": "WEB",
      "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aci-epgcbp-SfDU7NLf"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-20038 (GCVE-0-2026-20038)

Vulnerability from cvelistv5 – Published: 2026-10-07 16:11 – Updated: 2026-10-07 18:05

Title

Cisco Nexus 9000 Series Fabric Switches in ACI Mode Policy-Based Redirect Endpoint Group Contract Bypass Vulnerability

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.

Severity

5.8 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-07 18:02 UTC

CWE

CWE-284 - Improper Access Control

Assigner

cisco CNA under the mitre root

CNA scorecard C 66/100 over 376 records in the last 180 days details

References

1 reference

URL	Tags
https://sec.cloudapps.cisco.com/security/center/c…

Impacted products

1 product

Vendor	Product	Version
Cisco	Cisco NX-OS System Software in ACI Mode	Affected: 15.2(1g) Affected: 15.2(2e) Affected: 15.2(2f) Affected: 15.2(2g) Affected: 15.2(2h) Affected: 15.2(3f) Affected: 15.2(3e) Affected: 15.2(3g) Affected: 15.2(4d) Affected: 15.2(4e) Affected: 15.2(5c) Affected: 15.2(5d) Affected: 16.0(1g) Affected: 15.2(5e) Affected: 15.2(4f) Affected: 15.2(6e) Affected: 15.2(6h) Affected: 16.0(1j) Affected: 15.2(6g) Affected: 15.2(7f) Affected: 15.2(7g) Affected: 16.0(2h) Affected: 15.2(8d) Affected: 16.0(2j) Affected: 15.2(8e) Affected: 16.0(3d) Affected: 16.0(3e) Affected: 15.2(8f) Affected: 15.2(8g) Affected: 15.3(1d) Affected: 15.2(8h) Affected: 16.0(4c) Affected: 15.3(2a) Affected: 15.2(8i) Affected: 16.0(5h) Affected: 15.3(2b) Affected: 16.0(3g) Affected: 16.0(5j) Affected: 15.3(2c) Affected: 16.0(6c) Affected: 15.3(2d) Affected: 16.1(1f) Affected: 16.0(7e) Affected: 16.0(8e) Affected: 15.3(2e) Affected: 16.0(8f) Affected: 16.1(2f) Affected: 16.1(2g) Affected: 15.3(2f) Affected: 16.0(9c) Affected: 16.1(3f) Affected: 16.0(9d) Affected: 16.0(6h) Affected: 16.0(8h) Affected: 16.1(3g) Affected: 16.0(9e) Affected: 16.1(4h) Affected: 16.1(5e) Affected: 16.2(1g) Affected: 16.0(9f) Affected: 16.2(2e)

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-20038",
                "options": [
                  {
                    "Exploitation": "none"
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                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-07T18:02:43.242313Z",
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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              "version": "15.2(4d)"
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              "version": "15.2(4e)"
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            {
              "status": "affected",
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            },
            {
              "status": "affected",
              "version": "16.0(3d)"
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            {
              "status": "affected",
              "version": "16.0(3e)"
            },
            {
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              "status": "affected",
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              "status": "affected",
              "version": "16.0(3g)"
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              "status": "affected",
              "version": "16.0(5j)"
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              "status": "affected",
              "version": "15.3(2c)"
            },
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              "status": "affected",
              "version": "16.0(6c)"
            },
            {
              "status": "affected",
              "version": "15.3(2d)"
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            {
              "status": "affected",
              "version": "16.1(1f)"
            },
            {
              "status": "affected",
              "version": "16.0(7e)"
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              "status": "affected",
              "version": "16.0(8e)"
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            {
              "status": "affected",
              "version": "15.3(2e)"
            },
            {
              "status": "affected",
              "version": "16.0(8f)"
            },
            {
              "status": "affected",
              "version": "16.1(2f)"
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              "status": "affected",
              "version": "16.1(2g)"
            },
            {
              "status": "affected",
              "version": "15.3(2f)"
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              "status": "affected",
              "version": "16.0(9c)"
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            {
              "status": "affected",
              "version": "16.1(3f)"
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              "status": "affected",
              "version": "16.0(9d)"
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              "status": "affected",
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              "status": "affected",
              "version": "16.0(8h)"
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              "status": "affected",
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              "status": "affected",
              "version": "16.1(4h)"
            },
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              "status": "affected",
              "version": "16.1(5e)"
            },
            {
              "status": "affected",
              "version": "16.2(1g)"
            },
            {
              "status": "affected",
              "version": "16.0(9f)"
            },
            {
              "status": "affected",
              "version": "16.2(2e)"
            }
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          "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."
        }
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      "exploits": [
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    "state": "PUBLISHED"
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}

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.

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.

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GHSA-8R87-MJ76-XW8H

CVE-2026-20038 (GCVE-0-2026-20038)

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