Vulnerability-Lookup

CVE-2026-73446 (GCVE-0-2026-73446)

Vulnerability from cvelistv5 – Published: 2026-09-15 23:08 – Updated: 2026-09-16 19:34

Title

Security Advisory 0160

Summary

On affected platforms running Arista EOS with IS-IS configured on a broadcast interface, an unauthenticated attacker can send a crafted IS-IS Hello Protocol Data Unit (PDU) that causes the device to tear down an established IS-IS adjacency. This may result in traffic disruption and loss of IP reachability for prefixes advertised through that adjacency.

Severity

7.4 (High)


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

7 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-16 19:34 UTC

CWE

CWE-696 - Incorrect Behavior Order

Assigner

Arista mitre root

References

1 reference

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

Impacted products

1 product

Vendor	Product	Version	CPE status
Arista Networks	EOS	Affected: 4.36.0 , ≤ 4.36.1F (custom) Affected: 4.35.0 , ≤ 4.35.5M (custom) Affected: 4.34.0 , ≤ 4.34.7.1M (custom) Affected: 4.33.0 , ≤ 4.33.9M (custom) Affected: 4.32.0 , < 4.33.0F (custom) Affected: 4.31.0 , < 4.32.0F (custom)	guessed

Credits

This issue was discovered internally by Arista and the company is not aware of any malicious uses of these issues in customer networks.

Show details on NVD website

JSON

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              "value": "\u003cp\u003eIS-IS must be enabled on a broadcast (LAN) interface AND there should be an active IS-IS adjacency on that interface:\u003c/p\u003e\u003cpre\u003eswitch(config-router-isis)#show active\nrouter isis 1\n\u0026nbsp;\u0026nbsp;\u0026nbsp;net 49.0001.1111.1111.1001.00\nswitch(config-if-Et1)#show active\ninterface Ethernet1\n\u0026nbsp;\u0026nbsp;\u0026nbsp;isis enable 1\u003cbr\u003e\u003cbr\u003e\u003cpre\u003eswitch#show isis interface detail\nIS-IS Instance: 1 VRF: default\n\u003cbr\u003e\n\u0026nbsp;\u0026nbsp;Interface Ethernet1:\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Index: 4 SNPA: 2:2:0:1:0:0\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;MTU: 1497 Type: broadcast\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Supported address families: IPv4, IPv6\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Area proxy boundary is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;BFD IPv4 is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;BFD IPv6 is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Hello padding is enabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Level 1:\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Metric: 10, Number of adjacencies: 1\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;LAN-ID: 1111.1111.1001.04, Priority: 64\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;DIS: 1111.1111.1001, DIS priority: 64\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Authentication mode: None\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;TI-LFA protection is disabled for IPv4\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;TI-LFA protection is disabled for IPv6\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Adjacency 1111.1111.1002:\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;State: UP, Level: 1 Type: Level 1 IS\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Advertised hold time: 9\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Neighbor supported address families: IPv4, IPv6\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Address family match: Enabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;SNPA: 2:2:0:2:0:0, Priority: 64\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;IPv4 interface address: 10.0.0.2\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;IPv6 interface address: fe80::2:ff:fe02:0\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Area addresses: 49.0001\u003c/pre\u003e\u003c/pre\u003e\u003cp\u003eIf IS-IS is not configured OR IS-IS is configured only on point-to-point interfaces, there is no exposure to this issue.\u003cbr\u003e\u003cbr\u003e\u003c/p\u003e\u003cpre\u003eswitch#show isis interface detail\nIS-IS Instance: 1 VRF: default\n \n\u0026nbsp;\u0026nbsp;Interface Ethernet1:\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Index: 4 SNPA: P2P\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;MTU: 1497 Type: point-to-point\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Supported address families: IPv4, IPv6\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Area proxy boundary is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;BFD IPv4 is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;BFD IPv6 is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Hello padding is enabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Local fast flooding is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Level 1:\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Metric: 10, Number of adjacencies: 1\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Link-ID: 04\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Authentication mode: None\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;TI-LFA protection is disabled for IPv4\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;TI-LFA protection is disabled for IPv6\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Adjacency 1111.1111.1002:\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;State: UP, Level: 1 Type: Level 1 IS\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Advertised hold time: 30\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Neighbor supported address families: IPv4, IPv6\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Address family match: Enabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;IPv4 interface address: 1.0.0.2\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;IPv6 interface address: fe80::2:ff:fe02:0\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Area addresses: 49.0001\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Peer fast flooding is disabled\u003cbr\u003e\u003c/pre\u003e"
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          "value": "IS-IS must be enabled on a broadcast (LAN) interface AND there should be an active IS-IS adjacency on that interface:\n\n\n\nswitch(config-router-isis)#show active\nrouter isis 1\n\u00a0\u00a0\u00a0net 49.0001.1111.1111.1001.00\nswitch(config-if-Et1)#show active\ninterface Ethernet1\n\u00a0\u00a0\u00a0isis enable 1\n\n\n\nswitch#show isis interface detail\nIS-IS Instance: 1 VRF: default\n\n\n\u00a0\u00a0Interface Ethernet1:\n\u00a0\u00a0\u00a0\u00a0Index: 4 SNPA: 2:2:0:1:0:0\n\u00a0\u00a0\u00a0\u00a0MTU: 1497 Type: broadcast\n\u00a0\u00a0\u00a0\u00a0Supported address families: IPv4, IPv6\n\u00a0\u00a0\u00a0\u00a0Area proxy boundary is disabled\n\u00a0\u00a0\u00a0\u00a0BFD IPv4 is disabled\n\u00a0\u00a0\u00a0\u00a0BFD IPv6 is disabled\n\u00a0\u00a0\u00a0\u00a0Hello padding is enabled\n\u00a0\u00a0\u00a0\u00a0Level 1:\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Metric: 10, Number of adjacencies: 1\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0LAN-ID: 1111.1111.1001.04, Priority: 64\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0DIS: 1111.1111.1001, DIS priority: 64\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Authentication mode: None\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0TI-LFA protection is disabled for IPv4\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0TI-LFA protection is disabled for IPv6\n\u00a0\u00a0\u00a0\u00a0Adjacency 1111.1111.1002:\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0State: UP, Level: 1 Type: Level 1 IS\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Advertised hold time: 9\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Neighbor supported address families: IPv4, IPv6\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Address family match: Enabled\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0SNPA: 2:2:0:2:0:0, Priority: 64\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0IPv4 interface address: 10.0.0.2\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0IPv6 interface address: fe80::2:ff:fe02:0\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Area addresses: 49.0001\n\n\n\n\n\nIf IS-IS is not configured OR IS-IS is configured only on point-to-point interfaces, there is no exposure to this issue.\n\n\n\n\n\nswitch#show isis interface detail\nIS-IS Instance: 1 VRF: default\n \n\u00a0\u00a0Interface Ethernet1:\n\u00a0\u00a0\u00a0\u00a0Index: 4 SNPA: P2P\n\u00a0\u00a0\u00a0\u00a0MTU: 1497 Type: point-to-point\n\u00a0\u00a0\u00a0\u00a0Supported address families: IPv4, IPv6\n\u00a0\u00a0\u00a0\u00a0Area proxy boundary is disabled\n\u00a0\u00a0\u00a0\u00a0BFD IPv4 is disabled\n\u00a0\u00a0\u00a0\u00a0BFD IPv6 is disabled\n\u00a0\u00a0\u00a0\u00a0Hello padding is enabled\n\u00a0\u00a0\u00a0\u00a0Local fast flooding is disabled\n\u00a0\u00a0\u00a0\u00a0Level 1:\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Metric: 10, Number of adjacencies: 1\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Link-ID: 04\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Authentication mode: None\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0TI-LFA protection is disabled for IPv4\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0TI-LFA protection is disabled for IPv6\n\u00a0\u00a0\u00a0\u00a0Adjacency 1111.1111.1002:\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0State: UP, Level: 1 Type: Level 1 IS\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Advertised hold time: 30\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Neighbor supported address families: IPv4, IPv6\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Address family match: Enabled\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0IPv4 interface address: 1.0.0.2\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0IPv6 interface address: fe80::2:ff:fe02:0\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Area addresses: 49.0001\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Peer fast flooding is disabled"
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              "value": "\u003cp\u003eOn affected platforms running Arista EOS with IS-IS configured on a broadcast interface, an unauthenticated attacker can send a crafted IS-IS Hello Protocol Data Unit (PDU) that causes the device to tear down an established IS-IS adjacency. This may result in traffic disruption and loss of IP reachability for prefixes advertised through that adjacency.\u003c/p\u003e"
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                "baseSeverity": "HIGH",
                "confidentialityRequirement": "NOT_DEFINED",
                "exploitMaturity": "NOT_DEFINED",
                "integrityRequirement": "NOT_DEFINED",
                "modifiedAttackComplexity": "NOT_DEFINED",
                "modifiedAttackRequirements": "NOT_DEFINED",
                "modifiedAttackVector": "NOT_DEFINED",
                "modifiedPrivilegesRequired": "NOT_DEFINED",
                "modifiedSubAvailabilityImpact": "NOT_DEFINED",
                "modifiedSubConfidentialityImpact": "NOT_DEFINED",
                "modifiedSubIntegrityImpact": "NOT_DEFINED",
                "modifiedUserInteraction": "NOT_DEFINED",
                "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
                "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
                "modifiedVulnIntegrityImpact": "NOT_DEFINED",
                "privilegesRequired": "NONE",
                "providerUrgency": "NOT_DEFINED",
                "subAvailabilityImpact": "HIGH",
                "subConfidentialityImpact": "NONE",
                "subIntegrityImpact": "NONE",
                "userInteraction": "NONE",
                "valueDensity": "NOT_DEFINED",
                "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/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",
                "version": "4.0",
                "vulnAvailabilityImpact": "HIGH",
                "vulnConfidentialityImpact": "NONE",
                "vulnIntegrityImpact": "NONE",
                "vulnerabilityResponseEffort": "NOT_DEFINED"
              },
              "source": "psirt@arista.com",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-73446",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-16T19:34:09.117613Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-09-16T00:17:05.000",
        "references": [
          {
            "source": "psirt@arista.com",
            "url": "https://www.arista.com/en/support/advisories-notices/security-advisory/24716-security-advisory-0160"
          }
        ],
        "sourceIdentifier": "psirt@arista.com",
        "vulnStatus": "Awaiting Analysis",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-696"
              }
            ],
            "source": "psirt@arista.com",
            "type": "Secondary"
          }
        ]
      }
    },
    "vulnrichment": {
      "containers": {
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                    "id": "CVE-2026-73446",
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                    "version": "2.0.3"
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            "providerMetadata": {
              "dateUpdated": "2026-09-16T19:34:14.791Z",
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            },
            "title": "CISA ADP Vulnrichment"
          }
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        "cna": {
          "affected": [
            {
              "defaultStatus": "unaffected",
              "product": "EOS",
              "vendor": "Arista Networks",
              "versions": [
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                  "status": "affected",
                  "version": "4.36.0",
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                {
                  "lessThanOrEqual": "4.35.5M",
                  "status": "affected",
                  "version": "4.35.0",
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          "configurations": [
            {
              "lang": "en",
              "supportingMedia": [
                {
                  "base64": false,
                  "type": "text/html",
                  "value": "\u003cp\u003eIS-IS must be enabled on a broadcast (LAN) interface AND there should be an active IS-IS adjacency on that interface:\u003c/p\u003e\u003cpre\u003eswitch(config-router-isis)#show active\nrouter isis 1\n\u0026nbsp;\u0026nbsp;\u0026nbsp;net 49.0001.1111.1111.1001.00\nswitch(config-if-Et1)#show active\ninterface Ethernet1\n\u0026nbsp;\u0026nbsp;\u0026nbsp;isis enable 1\u003cbr\u003e\u003cbr\u003e\u003cpre\u003eswitch#show isis interface detail\nIS-IS Instance: 1 VRF: default\n\u003cbr\u003e\n\u0026nbsp;\u0026nbsp;Interface Ethernet1:\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Index: 4 SNPA: 2:2:0:1:0:0\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;MTU: 1497 Type: broadcast\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Supported address families: IPv4, IPv6\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Area proxy boundary is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;BFD IPv4 is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;BFD IPv6 is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Hello padding is enabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Level 1:\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Metric: 10, Number of adjacencies: 1\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;LAN-ID: 1111.1111.1001.04, Priority: 64\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;DIS: 1111.1111.1001, DIS priority: 64\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Authentication mode: None\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;TI-LFA protection is disabled for IPv4\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;TI-LFA protection is disabled for IPv6\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Adjacency 1111.1111.1002:\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;State: UP, Level: 1 Type: Level 1 IS\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Advertised hold time: 9\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Neighbor supported address families: IPv4, IPv6\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Address family match: Enabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;SNPA: 2:2:0:2:0:0, Priority: 64\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;IPv4 interface address: 10.0.0.2\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;IPv6 interface address: fe80::2:ff:fe02:0\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Area addresses: 49.0001\u003c/pre\u003e\u003c/pre\u003e\u003cp\u003eIf IS-IS is not configured OR IS-IS is configured only on point-to-point interfaces, there is no exposure to this issue.\u003cbr\u003e\u003cbr\u003e\u003c/p\u003e\u003cpre\u003eswitch#show isis interface detail\nIS-IS Instance: 1 VRF: default\n \n\u0026nbsp;\u0026nbsp;Interface Ethernet1:\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Index: 4 SNPA: P2P\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;MTU: 1497 Type: point-to-point\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Supported address families: IPv4, IPv6\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Area proxy boundary is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;BFD IPv4 is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;BFD IPv6 is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Hello padding is enabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Local fast flooding is disabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Level 1:\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Metric: 10, Number of adjacencies: 1\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Link-ID: 04\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Authentication mode: None\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;TI-LFA protection is disabled for IPv4\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;TI-LFA protection is disabled for IPv6\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Adjacency 1111.1111.1002:\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;State: UP, Level: 1 Type: Level 1 IS\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Advertised hold time: 30\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Neighbor supported address families: IPv4, IPv6\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Address family match: Enabled\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;IPv4 interface address: 1.0.0.2\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;IPv6 interface address: fe80::2:ff:fe02:0\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Area addresses: 49.0001\n\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Peer fast flooding is disabled\u003cbr\u003e\u003c/pre\u003e"
                }
              ],
              "value": "IS-IS must be enabled on a broadcast (LAN) interface AND there should be an active IS-IS adjacency on that interface:\n\n\n\nswitch(config-router-isis)#show active\nrouter isis 1\n\u00a0\u00a0\u00a0net 49.0001.1111.1111.1001.00\nswitch(config-if-Et1)#show active\ninterface Ethernet1\n\u00a0\u00a0\u00a0isis enable 1\n\n\n\nswitch#show isis interface detail\nIS-IS Instance: 1 VRF: default\n\n\n\u00a0\u00a0Interface Ethernet1:\n\u00a0\u00a0\u00a0\u00a0Index: 4 SNPA: 2:2:0:1:0:0\n\u00a0\u00a0\u00a0\u00a0MTU: 1497 Type: broadcast\n\u00a0\u00a0\u00a0\u00a0Supported address families: IPv4, IPv6\n\u00a0\u00a0\u00a0\u00a0Area proxy boundary is disabled\n\u00a0\u00a0\u00a0\u00a0BFD IPv4 is disabled\n\u00a0\u00a0\u00a0\u00a0BFD IPv6 is disabled\n\u00a0\u00a0\u00a0\u00a0Hello padding is enabled\n\u00a0\u00a0\u00a0\u00a0Level 1:\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Metric: 10, Number of adjacencies: 1\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0LAN-ID: 1111.1111.1001.04, Priority: 64\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0DIS: 1111.1111.1001, DIS priority: 64\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Authentication mode: None\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0TI-LFA protection is disabled for IPv4\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0TI-LFA protection is disabled for IPv6\n\u00a0\u00a0\u00a0\u00a0Adjacency 1111.1111.1002:\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0State: UP, Level: 1 Type: Level 1 IS\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Advertised hold time: 9\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Neighbor supported address families: IPv4, IPv6\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Address family match: Enabled\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0SNPA: 2:2:0:2:0:0, Priority: 64\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0IPv4 interface address: 10.0.0.2\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0IPv6 interface address: fe80::2:ff:fe02:0\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Area addresses: 49.0001\n\n\n\n\n\nIf IS-IS is not configured OR IS-IS is configured only on point-to-point interfaces, there is no exposure to this issue.\n\n\n\n\n\nswitch#show isis interface detail\nIS-IS Instance: 1 VRF: default\n \n\u00a0\u00a0Interface Ethernet1:\n\u00a0\u00a0\u00a0\u00a0Index: 4 SNPA: P2P\n\u00a0\u00a0\u00a0\u00a0MTU: 1497 Type: point-to-point\n\u00a0\u00a0\u00a0\u00a0Supported address families: IPv4, IPv6\n\u00a0\u00a0\u00a0\u00a0Area proxy boundary is disabled\n\u00a0\u00a0\u00a0\u00a0BFD IPv4 is disabled\n\u00a0\u00a0\u00a0\u00a0BFD IPv6 is disabled\n\u00a0\u00a0\u00a0\u00a0Hello padding is enabled\n\u00a0\u00a0\u00a0\u00a0Local fast flooding is disabled\n\u00a0\u00a0\u00a0\u00a0Level 1:\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Metric: 10, Number of adjacencies: 1\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Link-ID: 04\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Authentication mode: None\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0TI-LFA protection is disabled for IPv4\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0TI-LFA protection is disabled for IPv6\n\u00a0\u00a0\u00a0\u00a0Adjacency 1111.1111.1002:\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0State: UP, Level: 1 Type: Level 1 IS\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Advertised hold time: 30\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Neighbor supported address families: IPv4, IPv6\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Address family match: Enabled\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0IPv4 interface address: 1.0.0.2\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0IPv6 interface address: fe80::2:ff:fe02:0\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Area addresses: 49.0001\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Peer fast flooding is disabled"
            }
          ],
          "credits": [
            {
              "lang": "en",
              "type": "finder",
              "value": "This issue was discovered internally by Arista and the company is not aware of any malicious uses of these issues in customer networks."
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "supportingMedia": [
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                  "value": "\u003cp\u003eOn affected platforms running Arista EOS with IS-IS configured on a broadcast interface, an unauthenticated attacker can send a crafted IS-IS Hello Protocol Data Unit (PDU) that causes the device to tear down an established IS-IS adjacency. This may result in traffic disruption and loss of IP reachability for prefixes advertised through that adjacency.\u003c/p\u003e"
                }
              ],
              "value": "On affected platforms running Arista EOS with IS-IS configured on a broadcast interface, an unauthenticated attacker can send a crafted IS-IS Hello Protocol Data Unit (PDU) that causes the device to tear down an established IS-IS adjacency. This may result in traffic disruption and loss of IP reachability for prefixes advertised through that adjacency."
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              "capecId": "CAPEC-272",
              "descriptions": [
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          "metrics": [
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              "url": "https://www.arista.com/en/support/advisories-notices/security-advisory/24716-security-advisory-0160"
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        "assignerShortName": "Arista",
        "cveId": "CVE-2026-73446",
        "datePublished": "2026-09-15T23:08:19.771Z",
        "dateReserved": "2026-08-12T16:42:47.920Z",
        "dateUpdated": "2026-09-16T19:34:18.384Z",
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}

FKIE_CVE-2026-73446

Vulnerability from fkie_nvd - Published: 2026-09-16 00:17 - Updated: 2026-09-16 20:17

Severity

7.4 (High) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Summary

References

	URL	Tags
	psirt@arista.com	https://www.arista.com/en/support/advisories-notices/security-advisory/24716-security-advisory-0160

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "EOS",
          "vendor": "Arista Networks",
          "versions": [
            {
              "lessThanOrEqual": "4.36.1F",
              "status": "affected",
              "version": "4.36.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.35.5M",
              "status": "affected",
              "version": "4.35.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.34.7.1M",
              "status": "affected",
              "version": "4.34.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.33.9M",
              "status": "affected",
              "version": "4.33.0",
              "versionType": "custom"
            },
            {
              "lessThan": "4.33.0F",
              "status": "affected",
              "version": "4.32.0",
              "versionType": "custom"
            },
            {
              "lessThan": "4.32.0F",
              "status": "affected",
              "version": "4.31.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "psirt@arista.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "On affected platforms running Arista EOS with IS-IS configured on a broadcast interface, an unauthenticated attacker can send a crafted IS-IS Hello Protocol Data Unit (PDU) that causes the device to tear down an established IS-IS adjacency. This may result in traffic disruption and loss of IP reachability for prefixes advertised through that adjacency."
    }
  ],
  "id": "CVE-2026-73446",
  "lastModified": "2026-09-16T20:17:26.997",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.4,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 4.0,
        "source": "psirt@arista.com",
        "type": "Secondary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "ADJACENT",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 7.0,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/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",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "psirt@arista.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-73446",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-16T19:34:09.117613Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-16T00:17:05.000",
  "references": [
    {
      "source": "psirt@arista.com",
      "url": "https://www.arista.com/en/support/advisories-notices/security-advisory/24716-security-advisory-0160"
    }
  ],
  "sourceIdentifier": "psirt@arista.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-696"
        }
      ],
      "source": "psirt@arista.com",
      "type": "Secondary"
    }
  ]
}

GHSA-GQ4C-29W8-926P

Vulnerability from github – Published: 2026-09-16 00:31 – Updated: 2026-09-16 00:31

Details

Severity

7.4 (High)


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

7.0 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-73446"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-696"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-16T00:17:05Z",
    "severity": "HIGH"
  },
  "details": "On affected platforms running Arista EOS with IS-IS configured on a broadcast interface, an unauthenticated attacker can send a crafted IS-IS Hello Protocol Data Unit (PDU) that causes the device to tear down an established IS-IS adjacency. This may result in traffic disruption and loss of IP reachability for prefixes advertised through that adjacency.",
  "id": "GHSA-gq4c-29w8-926p",
  "modified": "2026-09-16T00:31:34Z",
  "published": "2026-09-16T00:31:34Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-73446"
    },
    {
      "type": "WEB",
      "url": "https://www.arista.com/en/support/advisories-notices/security-advisory/24716-security-advisory-0160"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/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"
    }
  ]
}

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.

Detection rules are retrieved from Rulezet.

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.

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.

Action not permitted

CVE-2026-73446 (GCVE-0-2026-73446)

FKIE_CVE-2026-73446

GHSA-GQ4C-29W8-926P

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Nomenclature

Related by attack behaviour