{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-73455","assignerOrgId":"c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7","state":"PUBLISHED","assignerShortName":"Arista","dateReserved":"2026-08-12T16:45:03.510Z","datePublished":"2026-09-16T09:46:15.888Z","dateUpdated":"2026-09-16T17:56:12.396Z"},"containers":{"cna":{"providerMetadata":{"orgId":"c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7","shortName":"Arista","dateUpdated":"2026-09-16T09:46:15.888Z"},"title":"Security Advisory 0173","descriptions":[{"lang":"en","value":"On affected platforms running Arista EOS with Open Shortest Path First version 3 (OSPFv3) configured, a specially crafted packet can cause the OSPFv3 agent to restart unexpectedly.","supportingMedia":[{"type":"text/html","base64":false,"value":"

On affected platforms running Arista EOS with Open Shortest Path First version 3 (OSPFv3) configured, a specially crafted packet can cause the OSPFv3 agent to restart unexpectedly.

"}]}],"affected":[{"vendor":"Arista Networks","product":"EOS","defaultStatus":"unaffected","versions":[{"version":"1.0.0","lessThan":"4.33.0F","status":"affected","versionType":"custom"},{"version":"4.33.0F","lessThanOrEqual":"4.33.8M","status":"affected","versionType":"custom"},{"version":"4.34.0F","lessThanOrEqual":"4.34.6M","status":"affected","versionType":"custom"},{"version":"4.35.0F","lessThanOrEqual":"4.35.4M","status":"affected","versionType":"custom"},{"version":"4.36.0F","lessThanOrEqual":"4.36.0.1F","status":"affected","versionType":"custom"}]}],"configurations":[{"lang":"en","value":"The vulnerability is exploitable when OSPFv3 is configured with at least one active neighbor:\n\nswitch>show ospfv3\nRouting Process \"ospfv3\" with ID 192.0.2.0 and Instance 0 VRF default\nIt has 1 fully adjacent neighbors\n\nswitch>show ospfv3 neighbor\nNeighbor 192.0.3.0 VRF default priority is 1, state is Full","supportingMedia":[{"type":"text/html","base64":false,"value":"

The vulnerability is exploitable when OSPFv3 is configured with at least one active neighbor:

\n
\nswitch>show ospfv3\nRouting Process "ospfv3" with ID 192.0.2.0 and Instance 0 VRF default\nIt has 1 fully adjacent neighbors\n\nswitch>show ospfv3 neighbor\nNeighbor 192.0.3.0 VRF default priority is 1, state is Full\n
"}]}],"workarounds":[{"lang":"en","value":"Configure OSPFv3 IPsec encryption to authenticate/encrypt OSPFv3 packets.\n\nPer-interface encryption:\n\nswitch(config)# interface \nswitch(config-if)# ospfv3 encryption ipsec spi esp aes-256-cbc sha1 passphrase \n\nPer-area encryption:\n\nswitch(config)# router ospfv3\nswitch(config-router-ospfv3)# address-family ipv4\nswitch(config-router-ospfv3-af)# area encryption ipsec spi esp aes-256-cbc sha1 passphrase ","supportingMedia":[{"type":"text/html","base64":false,"value":"

Configure OSPFv3 IPsec encryption to authenticate/encrypt OSPFv3 packets.

\n

Per-interface encryption:

\n
\nswitch(config)# interface <interface-name>\nswitch(config-if)# ospfv3 encryption ipsec spi <spi-value> esp aes-256-cbc sha1 passphrase <shared-passphrase>\n
\n

Per-area encryption:

\n
\nswitch(config)# router ospfv3\nswitch(config-router-ospfv3)# address-family ipv4\nswitch(config-router-ospfv3-af)# area <area-id> encryption ipsec spi <spi-value> esp aes-256-cbc sha1 passphrase <shared-passphrase>\n
"}]}],"solutions":[{"lang":"en","value":"The following EOS releases contain the fix:\n- 4.33.9M and later in the 4.33.x train\n- 4.34.7M and later in the 4.34.x train\n- 4.35.5M and later in the 4.35.x train\n- 4.36.1F and later in the 4.36.x train\n\nA hotfix (version 1.0) is available for 4.36.0.1F, 4.35.4M, 4.34.6M, and 4.33.8M.","supportingMedia":[{"type":"text/html","base64":false,"value":"

The following EOS releases contain the fix:

\n
    \n
  • 4.33.9M and later in the 4.33.x train
    • \n
  • 4.34.7M and later in the 4.34.x train
    • \n
  • 4.35.5M and later in the 4.35.x train
    • \n
  • 4.36.1F and later in the 4.36.x train
    • \n
\n

A hotfix (version 1.0) is available for 4.36.0.1F, 4.35.4M, 4.34.6M, and 4.33.8M.

"}]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H","baseScore":8.9,"baseSeverity":"HIGH"}}],"problemTypes":[{"descriptions":[{"lang":"en","type":"CWE","cweId":"CWE-130","description":"CWE-130 Improper Handling of Length Parameter Inconsistency"}]}],"references":[{"url":"https://www.arista.com/en/support/advisories-notices/security-advisory/24729-security-advisory-0173","tags":["vendor-advisory"]}],"impacts":[{"capecId":"CAPEC-231","descriptions":[{"lang":"en","value":"CAPEC-231 Oversized Serialized Data Payloads"}]}],"source":{"advisory":"Security Advisory 0173","discovery":"INTERNAL","defects":["BUG1307559"]},"datePublic":"2026-09-09T00:00:00.000Z"},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-16T17:56:02.507882Z","id":"CVE-2026-73455","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-09-16T17:56:12.396Z"}}]}}