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.
PUBLISHED5.2CWE-863
Security Advisory 0160
Problem type
Affected products
Arista Networks
EOS
<= 4.36.1F - AFFECTED
References
GitHub Security Advisories
GHSA-7q68-g5wg-74r4
On affected platforms running Arista EOS with IS-IS graceful restart enabled, an unauthenticated...
https://github.com/advisories/GHSA-7q68-g5wg-74r4On 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.
JSON source
https://cveawg.mitre.org/api/cve/CVE-2026-73460Click to expand
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"assignerShortName": "Arista",
"dateUpdated": "2026-09-15T23:20:43.813Z",
"dateReserved": "2026-08-12T16:45:03.511Z",
"datePublished": "2026-09-15T23:20:43.813Z",
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"value": "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.",
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"product": "EOS",
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"description": "CWE-863: Incorrect Authorization",
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"url": "https://www.arista.com/en/support/advisories-notices/security-advisory/24716-security-advisory-0160",
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"attackComplexity": "HIGH",
"privilegesRequired": "NONE",
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"scope": "CHANGED",
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"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.",
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"value": "<p>In order to be vulnerable to CVE-2026-73460, the following condition must be met: IS-IS graceful-restart should be enabled.</p><pre>switch(config-router-isis)#show active\nrouter isis 1\n net 49.0001.1111.1111.1001.00\n graceful-restart<br><br><pre>switch#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 </pre></pre><p>If IS-IS graceful-restart is not enabled, there is no exposure to this issue.</p>"
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"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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