Vulnerability-Lookup

GHSA-66C7-M7G9-9QRJ

Vulnerability from github – Published: 2026-09-15 21:31 – Updated: 2026-09-15 21:31

Details

On affected platforms running Arista EOS with dual switch cards and with ingress Security ACLs configured on Switched Virtual Interfaces (SVI) in shared mode, restarting of the secondary switchcard forwarding agent or insertion of secondary switchcard, can cause security ACLs on shared SVIs to stop functioning. This may result in incorrect packet permit/deny behavior.

This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.

Severity

4.8 (Medium)


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

6.3 (Medium)


                  
                    CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Show details on source website

JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-73451"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-15T19:17:38Z",
    "severity": "MODERATE"
  },
  "details": "On affected platforms running Arista EOS with dual switch cards and with ingress Security ACLs configured on Switched Virtual Interfaces (SVI) in shared mode, restarting of the secondary switchcard forwarding agent or insertion of secondary switchcard, can cause security ACLs on shared SVIs to stop functioning. This may result in incorrect packet permit/deny behavior.\n\nThis issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.",
  "id": "GHSA-66c7-m7g9-9qrj",
  "modified": "2026-09-15T21:31:20Z",
  "published": "2026-09-15T21:31:20Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-73451"
    },
    {
      "type": "WEB",
      "url": "https://www.arista.com/en/support/advisories-notices/security-advisory/24707-security-advisory-0151"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-73451 (GCVE-0-2026-73451)

Vulnerability from cvelistv5 – Published: 2026-09-15 18:12 – Updated: 2026-09-15 19:24

Title

Summary

Severity

4.8 (Medium)


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

6.3 (Medium)


                        
                          CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-15 19:24 UTC

CWE

CWE-1419 - Incorrect Initialization of Resource

Assigner

Arista mitre root

References

1 reference

URL	Tags
https://www.arista.com/en/support/advisories-noti…

Impacted products

1 product

Vendor	Product	Version
Arista Networks	EOS	Affected: 4.36.0 , ≤ 4.36.0.1F (custom) Affected: 4.35.0 , ≤ 4.35.4M (custom) Affected: 4.34.0 , ≤ 4.34.6M (custom) Affected: 4.33.0 , ≤ 4.33.8M (custom) Affected: 4.32.0 , ≤ 4.32.11M (custom) Affected: 4.31.1F , ≤ 4.31.10M (custom)

Date Public

2026-09-09 18:10

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-73451",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-15T19:24:36.704643Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-15T19:24:42.924Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "platforms": [
            "755 Series",
            "758 Series"
          ],
          "product": "EOS",
          "vendor": "Arista Networks",
          "versions": [
            {
              "lessThanOrEqual": "4.36.0.1F",
              "status": "affected",
              "version": "4.36.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.35.4M",
              "status": "affected",
              "version": "4.35.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.34.6M",
              "status": "affected",
              "version": "4.34.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.33.8M",
              "status": "affected",
              "version": "4.33.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.32.11M",
              "status": "affected",
              "version": "4.32.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.31.10M",
              "status": "affected",
              "version": "4.31.1F",
              "versionType": "custom"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cpre\u003e\u003cp\u003eIn order to be vulnerable to CVE-2026-73451, the following condition must be met:\u003c/p\u003e\u003cp\u003eSecurity ACL must be configured on SVI in ingress direction, which by default uses a shared ACL identifier. In the example below RACLID = 1 for both switchcards:\u003c/p\u003e\u003cpre\u003eswitch\u0026gt;show run interface vlan\ninterface Vlan100\n\u0026nbsp;\u0026nbsp;\u0026nbsp;ip access-group acl1 in\n  \nswitch\u0026gt;show platform trident tcam acl\u0026nbsp;\n=== IP ACLs on switch SwitchcardCes1/0 ===\n  \nINGRESS ACL acl1 uses 2 entries\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Assigned to VLANs: 100\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Shared ACL Identifier (RACLID): 1\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Assigned to ports: None\n  \n=== MAC ACLs on switch SwitchcardCes1/0 ===\n  \n=== IPv6 ACLs on switch SwitchcardCes1/0 ===\n  \n=== IP ACLs on switch SwitchcardCes2/0 ===\n  \nINGRESS ACL acl1 uses 2 entries\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Assigned to VLANs: 100\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Shared ACL Identifier (RACLID): 1\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Assigned to ports: None\n  \n=== MAC ACLs on switch SwitchcardCes2/0 ===\n  \n=== IPv6 ACLs on switch SwitchcardCes2/0 ===\n\u003c/pre\u003e\u003cdiv\u003e\u0026nbsp;\u003c/div\u003e\u003cp\u003eIf Security ACL is \u003cb\u003enot\u003c/b\u003e configured on SVI in ingress direction, there is no exposure to this issue and the message will look something like:\u003c/p\u003e\u003cpre\u003eswitch\u0026gt;show run interface vlan\ninterface Vlan100\n  \nswitch\u0026gt;show platform trident tcam acl\n=== IP ACLs on switch SwitchcardCes1/0 ===\n  \n=== MAC ACLs on switch SwitchcardCes1/0 ===\n  \n=== IPv6 ACLs on switch SwitchcardCes1/0 ===\n  \n=== IP ACLs on switch SwitchcardCes2/0 ===\n  \n=== MAC ACLs on switch SwitchcardCes2/0 ===\n  \n=== IPv6 ACLs on switch SwitchcardCes2/0 ===\u003c/pre\u003e\u003c/pre\u003e"
            }
          ],
          "value": "In order to be vulnerable to CVE-2026-73451, the following condition must be met:\n\n\n\nSecurity ACL must be configured on SVI in ingress direction, which by default uses a shared ACL identifier. In the example below RACLID = 1 for both switchcards:\n\n\n\nswitch\u003eshow run interface vlan\ninterface Vlan100\n\u00a0\u00a0\u00a0ip access-group acl1 in\n  \nswitch\u003eshow platform trident tcam acl\u00a0\n=== IP ACLs on switch SwitchcardCes1/0 ===\n  \nINGRESS ACL acl1 uses 2 entries\n\u00a0\u00a0\u00a0\u00a0Assigned to VLANs: 100\n\u00a0\u00a0\u00a0\u00a0Shared ACL Identifier (RACLID): 1\n\u00a0\u00a0\u00a0\u00a0Assigned to ports: None\n  \n=== MAC ACLs on switch SwitchcardCes1/0 ===\n  \n=== IPv6 ACLs on switch SwitchcardCes1/0 ===\n  \n=== IP ACLs on switch SwitchcardCes2/0 ===\n  \nINGRESS ACL acl1 uses 2 entries\n\u00a0\u00a0\u00a0\u00a0Assigned to VLANs: 100\n\u00a0\u00a0\u00a0\u00a0Shared ACL Identifier (RACLID): 1\n\u00a0\u00a0\u00a0\u00a0Assigned to ports: None\n  \n=== MAC ACLs on switch SwitchcardCes2/0 ===\n  \n=== IPv6 ACLs on switch SwitchcardCes2/0 ===\n\n\n\u00a0\n\n\n\nIf Security ACL is not configured on SVI in ingress direction, there is no exposure to this issue and the message will look something like:\n\n\n\nswitch\u003eshow run interface vlan\ninterface Vlan100\n  \nswitch\u003eshow platform trident tcam acl\n=== IP ACLs on switch SwitchcardCes1/0 ===\n  \n=== MAC ACLs on switch SwitchcardCes1/0 ===\n  \n=== IPv6 ACLs on switch SwitchcardCes1/0 ===\n  \n=== IP ACLs on switch SwitchcardCes2/0 ===\n  \n=== MAC ACLs on switch SwitchcardCes2/0 ===\n  \n=== IPv6 ACLs on switch SwitchcardCes2/0 ==="
        }
      ],
      "datePublic": "2026-09-09T18:10:00.000Z",
      "descriptions": [
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          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cpre\u003eOn affected platforms running Arista EOS with dual switch cards and with ingress Security ACLs configured on Switched Virtual Interfaces (SVI) in shared mode, restarting of the secondary switchcard forwarding agent or insertion of secondary switchcard, can cause security ACLs on shared SVIs to stop functioning. This may result in incorrect packet permit/deny behavior.\n\nThis issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.\n\u003c/pre\u003e"
            }
          ],
          "value": "On affected platforms running Arista EOS with dual switch cards and with ingress Security ACLs configured on Switched Virtual Interfaces (SVI) in shared mode, restarting of the secondary switchcard forwarding agent or insertion of secondary switchcard, can cause security ACLs on shared SVIs to stop functioning. This may result in incorrect packet permit/deny behavior.\n\nThis issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-180",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-180 Exploiting Incorrectly Configured Access Control Security Levels"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 4.8,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
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          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "HIGH",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.3,
            "baseSeverity": "MEDIUM",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "LOW",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1419",
              "description": "CWE-1419 Incorrect Initialization of Resource",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-15T18:12:44.908Z",
        "orgId": "c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7",
        "shortName": "Arista"
      },
      "references": [
        {
          "url": "https://www.arista.com/en/support/advisories-notices/security-advisory/24707-security-advisory-0151"
        }
      ],
      "solutions": [
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          "lang": "en",
          "supportingMedia": [
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              "value": "\u003cpre\u003e\nThe recommended resolution is to upgrade to a remediated software version at your earliest convenience. Arista recommends customers move to the latest version of each release that contains all the fixes listed below.\n\nCVE-2026-73451 has been fixed in the following releases:\n* 4.36.1F and later releases in the 4.36.x train.\n* 4.35.5M and later releases in the 4.35.x train.\n* 4.34.7M and later releases in the 4.34.x train.\n* 4.33.9M and later releases in the 4.33.x train.\n\u003c/pre\u003e"
            }
          ],
          "value": "The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Arista recommends customers move to the latest version of each release that contains all the fixes listed below.\n\nCVE-2026-73451 has been fixed in the following releases:\n* 4.36.1F and later releases in the 4.36.x train.\n* 4.35.5M and later releases in the 4.35.x train.\n* 4.34.7M and later releases in the 4.34.x train.\n* 4.33.9M and later releases in the 4.33.x train."
        }
      ],
      "source": {
        "advisory": "Security Advisory 0151",
        "defect": [
          "1262274"
        ],
        "defects": [
          "BUG 1262274"
        ],
        "discovery": "INTERNAL"
      },
      "title": "On affected platforms running Arista EOS with dual switch cards and with ingress Security ACLs configured on Switched Virtual Interfaces (SVI) in shared mode, restarting of the secondary switchcard forwarding agent or insertion of secondary switchcard, can",
      "workarounds": [
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              "value": "\u003cpre\u003e\u003cp\u003eThe workaround is to re-configure (remove and reapply) the ingress IPv4 and IPv6 ACLs applied to all SVIs.\u003c/p\u003e\u003cp\u003eFor every SVI check the active ACL(s) applied to it,\u003c/p\u003e\u003cpre\u003eswitch(config)# interface Vlan\u003ci\u003eNNN\u003c/i\u003e\nswitch(config-if-Vl\u003ci\u003eNNN\u003c/i\u003e)# show active\n\u003c/pre\u003e\u003cdiv\u003e\u0026nbsp;\u003c/div\u003e\u003cp\u003eThen remove the ACL(s) and re-apply them,\u003c/p\u003e\u003cpre\u003eswitch(config-if-Vl\u003ci\u003eNNN\u003c/i\u003e)# no ip access-group \u0026lt;acl name\u0026gt; in\nswitch(config-if-Vl\u003ci\u003eNNN\u003c/i\u003e)# ip access-group \u0026lt;acl name\u0026gt; in\nswitch(config-if-Vl\u003ci\u003eNNN\u003c/i\u003e)# no ipv6 access-group \u0026lt;acl name\u0026gt; in\nswitch(config-if-Vl\u003ci\u003eNNN\u003c/i\u003e)# ipv6 access-group \u0026lt;acl name\u0026gt; in\n\u003c/pre\u003e\u003cdiv\u003e\u0026nbsp;\u003c/div\u003e\u003cp\u003eNote: the security provided by the ACL configuration will not be present during the removal/reapplication of the security ACLs.\u003c/p\u003e\u003cp\u003eFor more information about Security ACLs see \u003ca href=\"https://www.arista.com/en/um-eos/eos-acls-and-route-maps\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eEOS User Manual: ACLs and Route Maps\u003c/a\u003e.\u003c/p\u003e\u003c/pre\u003e"
            }
          ],
          "value": "The workaround is to re-configure (remove and reapply) the ingress IPv4 and IPv6 ACLs applied to all SVIs.\n\n\n\nFor every SVI check the active ACL(s) applied to it,\n\n\n\nswitch(config)# interface VlanNNN\nswitch(config-if-VlNNN)# show active\n\n\n\u00a0\n\n\n\nThen remove the ACL(s) and re-apply them,\n\n\n\nswitch(config-if-VlNNN)# no ip access-group \u003cacl name\u003e in\nswitch(config-if-VlNNN)# ip access-group \u003cacl name\u003e in\nswitch(config-if-VlNNN)# no ipv6 access-group \u003cacl name\u003e in\nswitch(config-if-VlNNN)# ipv6 access-group \u003cacl name\u003e in\n\n\n\u00a0\n\n\n\nNote: the security provided by the ACL configuration will not be present during the removal/reapplication of the security ACLs.\n\n\n\nFor more information about Security ACLs see  EOS User Manual: ACLs and Route Maps https://www.arista.com/en/um-eos/eos-acls-and-route-maps ."
        }
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  "cveMetadata": {
    "assignerOrgId": "c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7",
    "assignerShortName": "Arista",
    "cveId": "CVE-2026-73451",
    "datePublished": "2026-09-15T18:12:44.908Z",
    "dateReserved": "2026-08-12T16:42:47.921Z",
    "dateUpdated": "2026-09-15T19:24:42.924Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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-66C7-M7G9-9QRJ

CVE-2026-73451 (GCVE-0-2026-73451)

Tags

Sightings

Nomenclature

Related by attack behaviour