CVE-2026-73439 (GCVE-0-2026-73439)
Vulnerability from cvelistv5 – Published: 2026-09-16 08:09 – Updated: 2026-09-16 08:09
VLAI
EPSS
VEX
Title
Security Advisory 0164
Summary
On affected platforms running Arista EOS, if OpenConfig is configured and running a gNMI server on the system, and if gNSI Pathz is configured and a gNSI Pathz policy is present on the system, then gNMI may fail to correctly enforce the rules in this policy if both a group rule and a user rule for the same path is present in the policy. Under certain conditions, this can lead to an authenticated user gaining unauthorized permission to read or write gNMI paths that the Pathz policy is intended to restrict.
Severity
CWE
- CWE-842 - Placement of User into Incorrect Group
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://www.arista.com/en/support/advisories-noti… | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Arista Networks | EOS |
Affected:
4.33.2F , ≤ 4.33.8M
(custom)
Affected: 4.34.0F , ≤ 4.34.6M (custom) Affected: 4.35.0F , ≤ 4.35.5M (custom) Affected: 4.36.0F , ≤ 4.36.0.1F (custom) |
guessed |
Date Public
2026-09-09 00:00
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"platforms": [
"710 Series",
"720D Series",
"720XP/722XPM Series",
"750X Series",
"7010TX Series",
"7020R/R4 Series",
"7130 Series (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"
],
"product": "EOS",
"vendor": "Arista Networks",
"versions": [
{
"lessThanOrEqual": "4.33.8M",
"status": "affected",
"version": "4.33.2F",
"versionType": "custom"
},
{
"lessThanOrEqual": "4.34.6M",
"status": "affected",
"version": "4.34.0F",
"versionType": "custom"
},
{
"lessThanOrEqual": "4.35.5M",
"status": "affected",
"version": "4.35.0F",
"versionType": "custom"
},
{
"lessThanOrEqual": "4.36.0.1F",
"status": "affected",
"version": "4.36.0F",
"versionType": "custom"
}
]
}
],
"configurations": [
{
"lang": "en",
"supportingMedia": [
{
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"type": "text/html",
"value": "\u003cp\u003eAll of the following conditions must be met for this vulnerability to be exploitable:\u003c/p\u003e\u003col\u003e\u003cli\u003eOpenConfig must be configured with a gNMI transport started. The running configuration will include:\u003cpre\u003e\nmanagement api gnmi\n transport grpc \u0026lt;name\u0026gt;\n\u003c/pre\u003e\u003c/li\u003e\u003cli\u003egNSI must be configured with the gNSI Pathz service enabled. The running configuration will include:\u003cpre\u003e\nmanagement api gnsi\n service pathz\n\u003c/pre\u003e\u003c/li\u003e\u003cli\u003eA Pathz policy must be present on the system at \u003ccode\u003e/persist/sys/gnsi/pathz/policy.json\u003c/code\u003e, and that policy must contain at least one group rule and at least one user rule for the same path.\u003c/li\u003e\u003c/ol\u003e\u003cp\u003eTo verify the presence of the policy file:\u003c/p\u003e\u003cpre\u003e\nswitch\u0026gt;enable\nswitch#bash stat /persist/sys/gnsi/pathz/policy.json\n\u003c/pre\u003e"
}
],
"value": "All of the following conditions must be met for this vulnerability to be exploitable:\n\n1. OpenConfig must be configured with a gNMI transport started. The running configuration will include:\n\n management api gnmi\n transport grpc \u003cname\u003e\n\n2. gNSI must be configured with the gNSI Pathz service enabled. The running configuration will include:\n\n management api gnsi\n service pathz\n\n3. A Pathz policy must be present on the system at /persist/sys/gnsi/pathz/policy.json, and that policy must contain at least one group rule and at least one user rule for the same path.\n\nTo verify the presence of the policy file:\n\n switch\u003eenable\n switch#bash stat /persist/sys/gnsi/pathz/policy.json"
}
],
"datePublic": "2026-09-09T00:00:00.000Z",
"descriptions": [
{
"lang": "en",
"supportingMedia": [
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"type": "text/html",
"value": "\u003cp\u003eOn affected platforms running Arista EOS, if OpenConfig is configured and running a gNMI server on the system, and if gNSI Pathz is configured and a gNSI Pathz policy is present on the system, then gNMI may fail to correctly enforce the rules in this policy if both a group rule and a user rule for the same path is present in the policy. Under certain conditions, this can lead to an authenticated user gaining unauthorized permission to read or write gNMI paths that the Pathz policy is intended to restrict.\u003c/p\u003e"
}
],
"value": "On affected platforms running Arista EOS, if OpenConfig is configured and running a gNMI server on the system, and if gNSI Pathz is configured and a gNSI Pathz policy is present on the system, then gNMI may fail to correctly enforce the rules in this policy if both a group rule and a user rule for the same path is present in the policy. Under certain conditions, this can lead to an authenticated user gaining unauthorized permission to read or write gNMI paths that the Pathz policy is intended to restrict."
}
],
"impacts": [
{
"capecId": "CAPEC-1",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs"
}
]
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
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"value": "GENERAL"
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{
"cvssV4_0": {
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "NETWORK",
"baseScore": 7.7,
"baseSeverity": "HIGH",
"privilegesRequired": "LOW",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "HIGH"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-842",
"description": "CWE-842 Placement of User into Incorrect Group",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-16T08:09:11.553Z",
"orgId": "c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7",
"shortName": "Arista"
},
"references": [
{
"name": "Arista Networks Security Advisory 0164",
"tags": [
"vendor-advisory"
],
"url": "https://www.arista.com/en/support/advisories-notices/security-advisory/24720-security-advisory-0164"
}
],
"solutions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eThe following EOS releases contain the fix for this vulnerability:\u003c/p\u003e\u003cul\u003e\u003cli\u003e4.33.9M and later releases in the 4.33.x train\u003c/li\u003e\u003cli\u003e4.34.7M and later releases in the 4.34.x train\u003c/li\u003e\u003cli\u003e4.35.6M and later releases in the 4.35.x train\u003c/li\u003e\u003cli\u003e4.36.1F and later releases in the 4.36.x train\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eNo hotfix is available for this vulnerability.\u003c/p\u003e"
}
],
"value": "The following EOS releases contain the fix for this vulnerability:\n - 4.33.9M and later releases in the 4.33.x train\n - 4.34.7M and later releases in the 4.34.x train\n - 4.35.6M and later releases in the 4.35.x train\n - 4.36.1F and later releases in the 4.36.x train\n\nNo hotfix is available for this vulnerability."
}
],
"source": {
"advisory": "Security Advisory 0164",
"defects": [
"BUG 1602638"
],
"discovery": "INTERNAL"
},
"title": "Security Advisory 0164",
"workarounds": [
{
"lang": "en",
"supportingMedia": [
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"base64": false,
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"value": "\u003cp\u003e\u003cstrong\u003eOption 1:\u003c/strong\u003e Disable gNSI Pathz entirely:\u003c/p\u003e\u003cpre\u003e\nswitch#configure\nswitch(config)#management api gnsi\nswitch(config-mgmt-api-gnsi)#no service pathz\n\u003c/pre\u003e\u003cp\u003e\u003cstrong\u003eOption 2:\u003c/strong\u003e Push a new gNSI Pathz policy that does not contain any group rules, using only user-principal rules. To push a new policy via grpcurl:\u003c/p\u003e\u003cpre\u003e\ngrpcurl -protoset ./pathz.proto.pb -H \u0027username:$USER\u0027 -v -d @ -plaintext $TARGET:$PORT gnsi.pathz.v1.Pathz/Rotate \u0026lt;\u0026lt; EOF\n{\n \"upload_request\": {\n \"version\": \"\u0026lt;version\u0026gt;\",\n \"created_on\": \u0026lt;timestamp\u0026gt;,\n \"policy\": \u0026lt;policy\u0026gt;\n }\n}\n{\n \"finalize_rotation\": {}\n}\nEOF\n\u003c/pre\u003e\u003cp\u003eEnsure all rules in the policy use \u003ccode\u003euser\u003c/code\u003e as the principal rather than \u003ccode\u003egroup\u003c/code\u003e to avoid triggering this vulnerability.\u003c/p\u003e"
}
],
"value": "Option 1: Disable gNSI Pathz entirely:\n\n switch#configure\n switch(config)#management api gnsi\n switch(config-mgmt-api-gnsi)#no service pathz\n\nOption 2: Push a new gNSI Pathz policy that does not contain any group rules, using only user-principal rules. To push a new policy via grpcurl:\n\n grpcurl -protoset ./pathz.proto.pb -H \u0027username:$USER\u0027 -v -d @ -plaintext $TARGET:$PORT gnsi.pathz.v1.Pathz/Rotate \u003c\u003c EOF\n {\n \"upload_request\": {\n \"version\": \"\u003cversion\u003e\",\n \"created_on\": \u003ctimestamp\u003e,\n \"policy\": \u003cpolicy\u003e\n }\n }\n {\n \"finalize_rotation\": {}\n }\n EOF\n\nEnsure all rules in the policy use \"user\" as the principal rather than \"group\" to avoid triggering this vulnerability."
}
]
}
},
"cveMetadata": {
"assignerOrgId": "c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7",
"assignerShortName": "Arista",
"cveId": "CVE-2026-73439",
"datePublished": "2026-09-16T08:09:11.553Z",
"dateReserved": "2026-08-12T16:39:35.977Z",
"dateUpdated": "2026-09-16T08:09:11.553Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-73439",
"date": "2026-09-16",
"epss": "0.00332",
"percentile": "0.26392"
},
"nvd": "{\"cve\":{\"id\":\"CVE-2026-73439\",\"sourceIdentifier\":\"psirt@arista.com\",\"published\":\"2026-09-16T09:17:04.687\",\"lastModified\":\"2026-09-16T09:17:04.687\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"On affected platforms running Arista EOS, if OpenConfig is configured and running a gNMI server on the system, and if gNSI Pathz is configured and a gNSI Pathz policy is present on the system, then gNMI may fail to correctly enforce the rules in this policy if both a group rule and a user rule for the same path is present in the policy. Under certain conditions, this can lead to an authenticated user gaining unauthorized permission to read or write gNMI paths that the Pathz policy is intended to restrict.\"}],\"affected\":[{\"source\":\"psirt@arista.com\",\"affectedData\":[{\"vendor\":\"Arista Networks\",\"product\":\"EOS\",\"defaultStatus\":\"unaffected\",\"platforms\":[\"710 Series\",\"720D Series\",\"720XP/722XPM Series\",\"750X Series\",\"7010TX Series\",\"7020R/R4 Series\",\"7130 Series (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\"],\"versions\":[{\"version\":\"4.33.2F\",\"lessThanOrEqual\":\"4.33.8M\",\"versionType\":\"custom\",\"status\":\"affected\"},{\"version\":\"4.34.0F\",\"lessThanOrEqual\":\"4.34.6M\",\"versionType\":\"custom\",\"status\":\"affected\"},{\"version\":\"4.35.0F\",\"lessThanOrEqual\":\"4.35.5M\",\"versionType\":\"custom\",\"status\":\"affected\"},{\"version\":\"4.36.0F\",\"lessThanOrEqual\":\"4.36.0.1F\",\"versionType\":\"custom\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"psirt@arista.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/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\":7.7,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"PRESENT\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"HIGH\",\"vulnIntegrityImpact\":\"HIGH\",\"vulnAvailabilityImpact\":\"HIGH\",\"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:H/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.6,\"impactScore\":5.9}]},\"weaknesses\":[{\"source\":\"psirt@arista.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-842\"}]}],\"references\":[{\"url\":\"https://www.arista.com/en/support/advisories-notices/security-advisory/24720-security-advisory-0164\",\"source\":\"psirt@arista.com\"}]}}"
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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