CVE-2026-73446 (GCVE-0-2026-73446)
Vulnerability from cvelistv5
Published
2026-09-15 23:08
Modified
2026-09-16 19:34
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
CWE
  • CWE-696 - Incorrect Behavior Order
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.
References
Impacted products
Vendor Product Version
Arista Networks EOS Version: 4.36.0   <
Version: 4.35.0   <
Version: 4.34.0   <
Version: 4.33.0   <
Version: 4.32.0   < 4.33.0F
Version: 4.31.0   < 4.32.0F
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                "id": "CVE-2026-73446",
                "options": [
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                    "Exploitation": "none"
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                    "Automatable": "no"
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                  {
                    "Technical Impact": "partial"
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                "role": "CISA Coordinator",
                "timestamp": "2026-09-16T19:34:09.117613Z",
                "version": "2.0.3"
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
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        "title": "CISA ADP Vulnrichment"
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      "affected": [
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          "product": "EOS",
          "vendor": "Arista Networks",
          "versions": [
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              "lessThanOrEqual": "4.36.1F",
              "status": "affected",
              "version": "4.36.0",
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              "version": "4.35.0",
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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"
        }
      ],
      "credits": [
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          "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."
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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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          "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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            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
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            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
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    "assignerShortName": "Arista",
    "cveId": "CVE-2026-73446",
    "datePublished": "2026-09-15T23:08:19.771Z",
    "dateReserved": "2026-08-12T16:42:47.920Z",
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  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-73446\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-09-16T19:34:09.117613Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-09-16T19:34:14.791Z\"}}], \"cna\": {\"title\": \"Security Advisory 0160\", \"source\": {\"defects\": [\"BUG1840504\"], \"advisory\": \"0160\", \"discovery\": \"UNKNOWN\"}, \"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.\"}], \"impacts\": [{\"capecId\": \"CAPEC-272\", \"descriptions\": [{\"lang\": \"en\", \"value\": \"CAPEC-272 Protocol Manipulation\"}]}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV3_1\": {\"scope\": \"CHANGED\", \"version\": \"3.1\", \"baseScore\": 7.4, \"attackVector\": \"ADJACENT_NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}, {\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 7, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"ADJACENT\", \"baseSeverity\": \"HIGH\", \"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\", \"exploitMaturity\": \"NOT_DEFINED\", \"providerUrgency\": \"NOT_DEFINED\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"PRESENT\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"HIGH\", \"vulnAvailabilityImpact\": \"HIGH\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"NONE\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"vendor\": \"Arista Networks\", \"product\": \"EOS\", \"versions\": [{\"status\": \"affected\", \"version\": \"4.36.0\", \"versionType\": \"custom\", \"lessThanOrEqual\": \"4.36.1F\"}, {\"status\": \"affected\", \"version\": \"4.35.0\", \"versionType\": \"custom\", \"lessThanOrEqual\": \"4.35.5M\"}, {\"status\": \"affected\", \"version\": \"4.34.0\", \"versionType\": \"custom\", \"lessThanOrEqual\": \"4.34.7.1M\"}, {\"status\": \"affected\", \"version\": \"4.33.0\", \"versionType\": \"custom\", \"lessThanOrEqual\": \"4.33.9M\"}, {\"status\": \"affected\", \"version\": \"4.32.0\", \"lessThan\": \"4.33.0F\", \"versionType\": \"custom\"}, {\"status\": \"affected\", \"version\": \"4.31.0\", \"lessThan\": \"4.32.0F\", \"versionType\": \"custom\"}], \"defaultStatus\": \"unaffected\"}], \"solutions\": [{\"lang\": \"en\", \"value\": \"The recommended resolution is to upgrade to a fixed software version.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eThe recommended resolution is to upgrade to a fixed software version.\u003c/p\u003e\", \"base64\": false}]}], \"references\": [{\"url\": \"https://www.arista.com/en/support/advisories-notices/security-advisory/24716-security-advisory-0160\", \"name\": \"Security Advisory 0160\", \"tags\": [\"vendor-advisory\"]}], \"workarounds\": [{\"lang\": \"en\", \"value\": \"No workaround is available for this issue.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eNo workaround is available for this issue.\u003c/p\u003e\", \"base64\": false}]}], \"x_generator\": {\"engine\": \"Vulnogram 1.0.5\"}, \"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.\", \"supportingMedia\": [{\"type\": \"text/html\", \"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\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-696\", \"description\": \"CWE-696: Incorrect Behavior Order\"}]}], \"configurations\": [{\"lang\": \"en\", \"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\", \"supportingMedia\": [{\"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\", \"base64\": false}]}], \"providerMetadata\": {\"orgId\": \"c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7\", \"shortName\": \"Arista\", \"dateUpdated\": \"2026-09-15T23:08:19.771Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-73446\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-09-16T19:34:18.384Z\", \"dateReserved\": \"2026-08-12T16:42:47.920Z\", \"assignerOrgId\": \"c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7\", \"datePublished\": \"2026-09-15T23:08:19.771Z\", \"assignerShortName\": \"Arista\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


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  • 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.
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  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.