In order to be vulnerable to CVE-2026-73445, gNSI Authz must be configured on an OpenConfig gRPC transport:
switch#show man api gnsi\nTransport: default\nTransport enabled: yes\nServer: running on port 6030, 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"}],"value":"In order to be vulnerable to CVE-2026-73445, gNSI Authz must be configured on an OpenConfig gRPC transport:\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 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"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"
On affected platforms running Arista EOS, an issue with the gRPC Network Security Interface (gNSI) Authz Rotate RPC may cause an incorrect Authz policy which was uploaded in the ongoing RPC stream to become active. This does not affect Bootz.
This issue was discovered internally by Arista and the company is not aware of any malicious uses of this issue in customer networks.
"}],"value":"On affected platforms running Arista EOS, an issue with the gRPC Network Security Interface (gNSI) Authz Rotate RPC may cause an incorrect Authz policy which was uploaded in the ongoing RPC stream to become active. This does not affect Bootz.\n\nThis issue was discovered internally by Arista and the company is not aware of any malicious uses of this issue in customer networks."}],"metrics":[{"cvssV3_1":{"baseScore":4.9,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]},{"cvssV4_0":{"baseScore":6.9,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","description":"CWE-20 Improper Input Validation","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-09-16T10:13:37.145Z","orgId":"c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7","shortName":"Arista"},"references":[{"name":"Security Advisory 0167","tags":["vendor-advisory"],"url":"https://www.arista.com/en/support/advisories-notices/security-advisory/24723-security-advisory-0167"}],"solutions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","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-2026-73445 has been fixed in the following releases:
No hotfix is available for this issue.
"}],"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-2026-73445 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- 4.34.8M 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."}],"source":{"advisory":"Security Advisory 0167","defects":["BUG 1602625"],"discovery":"INTERNAL"},"title":"Security Advisory 0167","workarounds":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"1. Include exactly one UploadRequest in a gNSI Authz Rotate request.
2. Use a gNSI Authz policy that restricts gNSI Authz use to only those who strictly need it. Below is an example policy that only allows user "Neo" to rotate Authz policies:
{\n \"name\":\"restrict-authz-policy\",\n \"allow_rules\":[\n {\n \"name\":\"neoallow\",\n \"request\":{\n \"paths\":[\n \"/gnsi.authz.v1.Authz/Rotate\"\n ],\n \"headers\":[\n {\n \"key\":\"username\",\n \"values\":[\n \"Neo\"\n ]\n }\n ]\n }\n },\n {\n \"name\":\"allow-gnmi\",\n \"request\":{\n \"paths\":[\n \"/gnmi.gNMI/*\"\n ]\n }\n },\n {\n \"name\":\"allow-gnoi\",\n \"request\":{\n \"paths\":[\n \"/gnoi.*\"\n ]\n }\n }\n ]\n}Ideally, this policy would be uploaded via a gNSI client for correct version and created-on metadata handling. However, the policy can also be written directly to the active policy file:
switch#bash timeout 100 echo \"{\\\"name\\\":\\\"restrict-authz-policy\\\",\\\"allow_rules\\\":[{\\\"name\\\":\\\"neoallow\\\",\\\"request\\\":{\\\"paths\\\":[\\\"\\/gnsi.authz.v1.Authz\\/Rotate\\\"],\\\"headers\\\":[{\\\"key\\\":\\\"username\\\",\\\"values\\\":[\\\"Neo\\\"]}]}},{\\\"name\\\":\\\"allow-gnmi\\\",\\\"request\\\":{\\\"paths\\\":[\\\"\\/gnmi.gNMI\\/*\\\"]}},{\\\"name\\\":\\\"allow-gnoi\\\",\\\"request\\\":{\\\"paths\\\":[\\\"\\/gnoi.*\\\"]}}]}\" | sudo tee /persist/sys/gnsi/authz/policy.json && sleep 11"}],"value":"1. Include exactly one UploadRequest in a gNSI Authz Rotate request.\n\n2. Use a gNSI Authz policy that restricts gNSI Authz use to only those who strictly need it. Below is an example policy that only allows user \"Neo\" to rotate Authz policies:\n\n {\n \"name\":\"restrict-authz-policy\",\n \"allow_rules\":[\n {\n \"name\":\"neoallow\",\n \"request\":{\n \"paths\":[\n \"/gnsi.authz.v1.Authz/Rotate\"\n ],\n \"headers\":[\n {\n \"key\":\"username\",\n \"values\":[\n \"Neo\"\n ]\n }\n ]\n }\n },\n {\n \"name\":\"allow-gnmi\",\n \"request\":{\n \"paths\":[\n \"/gnmi.gNMI/*\"\n ]\n }\n },\n {\n \"name\":\"allow-gnoi\",\n \"request\":{\n \"paths\":[\n \"/gnoi.*\"\n ]\n }\n }\n ]\n }\n\nIdeally, this policy would be uploaded via a gNSI client for correct version and created-on metadata handling. However, the policy can also be written directly to the active policy file:\n\n switch#bash timeout 100 echo \"{\\\"name\\\":\\\"restrict-authz-policy\\\",\\\"allow_rules\\\":[{\\\"name\\\":\\\"neoallow\\\",\\\"request\\\":{\\\"paths\\\":[\\\"\\/gnsi.authz.v1.Authz\\/Rotate\\\"],\\\"headers\\\":[{\\\"key\\\":\\\"username\\\",\\\"values\\\":[\\\"Neo\\\"]}]}},{\\\"name\\\":\\\"allow-gnmi\\\",\\\"request\\\":{\\\"paths\\\":[\\\"\\/gnmi.gNMI\\/*\\\"]}},{\\\"name\\\":\\\"allow-gnoi\\\",\\\"request\\\":{\\\"paths\\\":[\\\"\\/gnoi.*\\\"]}}]}\" | sudo tee /persist/sys/gnsi/authz/policy.json && sleep 11"}]}},"cveMetadata":{"assignerOrgId":"c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7","assignerShortName":"Arista","cveId":"CVE-2026-73445","datePublished":"2026-09-16T08:58:51.242Z","dateReserved":"2026-08-12T16:42:47.920Z","dateUpdated":"2026-09-16T17:35:56.813Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-16 09:17:04","lastModifiedDate":"2026-09-16 19:09:28","problem_types":["CWE-20","CWE-20 CWE-20 Improper Input Validation"],"metrics":{"cvssMetricV40":[{"source":"psirt@arista.com","type":"Secondary","cvssData":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","baseScore":6.9,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"HIGH","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"cvssMetricV31":[{"source":"psirt@arista.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N","baseScore":4.9,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"HIGH","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE"},"exploitabilityScore":1.2,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-16T17:35:46.330735Z","id":"CVE-2026-73445","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"73445","Ordinal":"1","Title":"Security Advisory 0167","CVE":"CVE-2026-73445","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"73445","Ordinal":"1","NoteData":"On affected platforms running Arista EOS, an issue with the gRPC Network Security Interface (gNSI) Authz Rotate RPC may cause an incorrect Authz policy which was uploaded in the ongoing RPC stream to become active. This does not affect Bootz.\n\nThis issue was discovered internally by Arista and the company is not aware of any malicious uses of this issue in customer networks.","Type":"Description","Title":"Security Advisory 0167"}]}}}