{"id":"CVE-2026-73455","state":"PUBLISHED","title":"Security Advisory 0173","description":"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.","publishedAt":"2026-09-16T09:46:15.888Z","updatedAt":"2026-09-16T17:56:12.396Z","severity":{"score":8.9,"label":"High","version":"4.0","vector":"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","source":"Arista"},"assigner":"Arista","products":["Arista Networks EOS"],"affected":[{"vendor":"Arista Networks","product":"EOS","defaultStatus":"unaffected","versions":[{"version":"1.0.0","status":"affected","lessThan":"4.33.0F","versionType":"custom"},{"version":"4.33.0F","status":"affected","lessThanOrEqual":"4.33.8M","versionType":"custom"},{"version":"4.34.0F","status":"affected","lessThanOrEqual":"4.34.6M","versionType":"custom"},{"version":"4.35.0F","status":"affected","lessThanOrEqual":"4.35.4M","versionType":"custom"},{"version":"4.36.0F","status":"affected","lessThanOrEqual":"4.36.0.1F","versionType":"custom"}]}],"references":["https://www.arista.com/en/support/advisories-notices/security-advisory/24729-security-advisory-0173"],"weaknesses":["CWE-130"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/73xxx/CVE-2026-73455.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-73455","state":"PUBLISHED","datePublished":"2026-09-16T09:46:15.888Z","dateUpdated":"2026-09-16T17:56:12.396Z","assignerShortName":"Arista","assignerOrgId":"c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7","dateReserved":"2026-08-12T16:45:03.510Z"},"containers":{"cna":{"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."}],"affected":[{"vendor":"Arista Networks","product":"EOS","defaultStatus":"unaffected","versions":[{"version":"1.0.0","status":"affected","lessThan":"4.33.0F","versionType":"custom"},{"version":"4.33.0F","status":"affected","lessThanOrEqual":"4.33.8M","versionType":"custom"},{"version":"4.34.0F","status":"affected","lessThanOrEqual":"4.34.6M","versionType":"custom"},{"version":"4.35.0F","status":"affected","lessThanOrEqual":"4.35.4M","versionType":"custom"},{"version":"4.36.0F","status":"affected","lessThanOrEqual":"4.36.0.1F","versionType":"custom"}]}],"references":[{"url":"https://www.arista.com/en/support/advisories-notices/security-advisory/24729-security-advisory-0173","tags":["vendor-advisory"]}],"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":[{"cweId":"CWE-130","lang":"en","type":"CWE","description":"CWE-130 Improper Handling of Length Parameter Inconsistency"}]}],"providerMetadata":{"shortName":"Arista","orgId":"c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7","dateUpdated":"2026-09-16T09:46:15.888Z"},"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":"<p>The vulnerability is exploitable when OSPFv3 is configured with at least one active neighbor:</p>\n<pre>\nswitch&gt;show ospfv3\nRouting Process &quot;ospfv3&quot; with ID 192.0.2.0 and Instance 0 VRF default\nIt has 1 fully adjacent neighbors\n\nswitch&gt;show ospfv3 neighbor\nNeighbor 192.0.3.0 VRF default priority is 1, state is Full\n</pre>"}]}],"workarounds":[{"lang":"en","value":"Configure OSPFv3 IPsec encryption to authenticate/encrypt OSPFv3 packets.\n\nPer-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\nPer-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>","supportingMedia":[{"type":"text/html","base64":false,"value":"<p>Configure OSPFv3 IPsec encryption to authenticate/encrypt OSPFv3 packets.</p>\n<p>Per-interface encryption:</p>\n<pre>\nswitch(config)# interface &lt;interface-name&gt;\nswitch(config-if)# ospfv3 encryption ipsec spi &lt;spi-value&gt; esp aes-256-cbc sha1 passphrase &lt;shared-passphrase&gt;\n</pre>\n<p>Per-area encryption:</p>\n<pre>\nswitch(config)# router ospfv3\nswitch(config-router-ospfv3)# address-family ipv4\nswitch(config-router-ospfv3-af)# area &lt;area-id&gt; encryption ipsec spi &lt;spi-value&gt; esp aes-256-cbc sha1 passphrase &lt;shared-passphrase&gt;\n</pre>"}]}],"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":"<p>The following EOS releases contain the fix:</p>\n<ul>\n<li>4.33.9M and later in the 4.33.x train</li>\n<li>4.34.7M and later in the 4.34.x train</li>\n<li>4.35.5M and later in the 4.35.x train</li>\n<li>4.36.1F and later in the 4.36.x train</li>\n</ul>\n<p>A hotfix (version 1.0) is available for 4.36.0.1F, 4.35.4M, 4.34.6M, and 4.33.8M.</p>"}]}],"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":[{"title":"CISA ADP Vulnrichment","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"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-16T17:56:12.396Z"}}]}}}