On affected platforms running Arista EOS with IS-IS graceful restart enabled, an unauthenticated attacker who can inject a malformed IS-IS LSP PDU packet can cause the IS-IS graceful restart procedure to terminate prematurely. This may result in traffic loss following a restart event.
"}]}],"references":[{"url":"https://www.arista.com/en/support/advisories-notices/security-advisory/24716-security-advisory-0160","name":"Security Advisory 0160","tags":["vendor-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"ADJACENT_NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseSeverity":"MEDIUM","baseScore":6.1,"vectorString":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"ADJACENT","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"HIGH","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":7,"vectorString":"CVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H"}}],"configurations":[{"lang":"en","value":"In order to be vulnerable to CVE-2026-73460, the following condition must be met: IS-IS graceful-restart should be enabled.\n\n\n\nswitch(config-router-isis)#show active\nrouter isis 1\n net 49.0001.1111.1111.1001.00\n graceful-restart\n\n\n\nswitch#show isis graceful-restart\nIS-IS Instance: 1 VRF: default\n System ID: 1111.1111.1001\n Graceful Restart: Enabled, Graceful Restart Helper: Enabled\n State: Graceful Restart disabled during startup\n T1 : 3s\n T2 (level-1) : 30s/not running\n T2 (level-2) : 30s/not running\n T3 : not running\n System ID Type Interface Restart Capable Status \n 1111.1111.1002 L1 Ethernet1 Yes Running \n\n\n\n\n\nIf IS-IS graceful-restart is not enabled, there is no exposure to this issue.","supportingMedia":[{"type":"text/html","base64":false,"value":"In order to be vulnerable to CVE-2026-73460, the following condition must be met: IS-IS graceful-restart should be enabled.
switch(config-router-isis)#show active\nrouter isis 1\n net 49.0001.1111.1111.1001.00\n graceful-restartswitch#show isis graceful-restart\nIS-IS Instance: 1 VRF: default\n System ID: 1111.1111.1001\n Graceful Restart: Enabled, Graceful Restart Helper: Enabled\n State: Graceful Restart disabled during startup\n T1 : 3s\n T2 (level-1) : 30s/not running\n T2 (level-2) : 30s/not running\n T3 : not running\n System ID Type Interface Restart Capable Status \n 1111.1111.1002 L1 Ethernet1 Yes Running
If IS-IS graceful-restart is not enabled, there is no exposure to this issue.
"}]}],"workarounds":[{"lang":"en","value":"No workaround is available for this issue.","supportingMedia":[{"type":"text/html","base64":false,"value":"No workaround is available for this issue.
"}]}],"solutions":[{"lang":"en","value":"The recommended resolution is to upgrade to a fixed software version.","supportingMedia":[{"type":"text/html","base64":false,"value":"The recommended resolution is to upgrade to a fixed software version.
"}]}],"credits":[{"lang":"en","value":"This issue was discovered internally by Arista and the company is not aware of any malicious uses of these issues in customer networks.","type":"finder"}],"source":{"advisory":"0160","discovery":"UNKNOWN","defects":["BUG1840562"]},"x_generator":{"engine":"Vulnogram 1.0.5"}}}}