On affected platforms running Arista EOS, when multiple gRPC Network Security Interface (gNSI) transports are configured, a race condition in the gNSI Authz service may cause a policy rotation to fail silently. An authenticated user whose access was revoked by the new policy may retain unauthorized access to gRPC interfaces. This does not affect Bootz.
This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.
"}]}],"affected":[{"vendor":"Arista Networks","product":"EOS","defaultStatus":"unaffected","versions":[{"version":"4.36.0F","lessThanOrEqual":"4.36.0.1F","status":"affected","versionType":"custom"},{"version":"4.35.0F","lessThanOrEqual":"4.35.5M","status":"affected","versionType":"custom"},{"version":"4.34.0F","lessThanOrEqual":"4.34.7M","status":"affected","versionType":"custom"},{"version":"4.33.0F","lessThanOrEqual":"4.33.8M","status":"affected","versionType":"custom"},{"version":"4.32.0F","lessThanOrEqual":"4.32.11M","status":"affected","versionType":"custom"},{"version":"4.31.0F","lessThanOrEqual":"4.31.10M","status":"affected","versionType":"custom"}],"platforms":["710 Series","720D Series","720XP/722XPM Series","750X Series","7010TX Series","7020R/R4 Series","7130 Series running EOS","7170 Series","7050X3/X4 Series","7060X/X2/X4/X5/X6 Series","7260X/X3 Series","7280R/R2/R3/R4 Series","7300X/X3 Series","7320X Series","7358X4 Series","7368X4 Series","7388X5 Series","7500R/R2/R3 Series","7800R3/R4 Series","7700R4 Series","AWE 5000 Series","AWE 7200R Series","CloudEOS","cEOS-lab","vEOS-lab","CloudVision eXchange, virtual or physical appliance"]}],"configurations":[{"lang":"en","value":"In order to be vulnerable to CVE-2026-73463, gNSI Authz must be enabled with multiple transports configured:\n\n switch#show man api gnsi\n Transport: default\n Transport enabled: yes\n Server: running on port 6030, in default VRF\n\n Transport: other\n Transport enabled: yes\n Server: running on port 6031, in default VRF\n\n Acctz enabled: no\n Attestz enabled: no\n Authz enabled: yes\n Certz enabled: no\n Credentialz enabled: no\n Enrollz enabled: no\n Pathz enabled: no\n\nPlease note that a system may have been affected by this vulnerability if a secondary transport (such as the \"other\" transport in the preceding example) was configured at any point. The running configuration on the system may have subsequently been modified to remove this secondary transport.","supportingMedia":[{"type":"text/html","base64":false,"value":"In order to be vulnerable to CVE-2026-73463, gNSI Authz must be enabled with multiple transports configured:
switch#show man api gnsi\nTransport: default\nTransport enabled: yes\nServer: running on port 6030, in default VRF\n\nTransport: other\nTransport enabled: yes\nServer: running on port 6031, in default VRF\n\nAcctz enabled: no\nAttestz enabled: no\nAuthz enabled: yes\nCertz enabled: no\nCredentialz enabled: no\nEnrollz enabled: no\nPathz enabled: no
Please note that a system may have been affected by this vulnerability if a secondary transport (such as the "other" transport in the preceding example) was configured at any point. The running configuration on the system may have subsequently been modified to remove this secondary transport.
"}]}],"workarounds":[{"lang":"en","value":"Restrict the set of users that can enable gNSI on OpenConfig / Octa transports via the CLI.\n\nFirstly, configure AAA authorization. The following is an example of configuring AAA authorization for all privilege levels using only the local user database:\n\n switch(config)#aaa authorization commands all default local\n switch(config)#aaa authorization config-commands\n\nNow restrict a sufficient subset of all roles from enabling gNSI services. In the below example, we prohibit just network-operators:\n\n switch(config-mgmt-api-gnsi)#role network-operator\n switch(config-role-network-operator)#10 deny mode mgmt-api-gnsi command transport gnmi .*\n 256 permit command .*","supportingMedia":[{"type":"text/html","base64":false,"value":"Restrict the set of users that can enable gNSI on OpenConfig / Octa transports via the CLI.
Firstly, configure AAA authorization. The following is an example of configuring AAA authorization for all privilege levels using only the local user database:
switch(config)#aaa authorization commands all default local\nswitch(config)#aaa authorization config-commands
Now restrict a sufficient subset of all roles from enabling gNSI services. In the below example, we prohibit just network-operators:
switch(config-mgmt-api-gnsi)#role network-operator\nswitch(config-role-network-operator)#10 deny mode mgmt-api-gnsi command transport gnmi .*\n256 permit command .*"}]}],"solutions":[{"lang":"en","value":"The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Arista recommends customers move to the latest version of each release that contains all the fixes listed below.\n\nCVE-2026-73463 has been fixed in the following releases:\n- 4.36.1F and later releases in the 4.36.x train\n- 4.35.6M and later releases in the 4.35.x train\n- 4.34.7.1M and later releases in the 4.34.x train\n- 4.33.9M and later releases in the 4.33.x train\n\nNo hotfix is available for this issue.","supportingMedia":[{"type":"text/html","base64":false,"value":"
The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Arista recommends customers move to the latest version of each release that contains all the fixes listed below.
CVE-2026-73463 has been fixed in the following releases:
No hotfix is available for this issue.
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