Description
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 An authenticated user whose access was revoked by the new policy may retain unauthorized access to gRPC interfaces.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.
Published: 2026-09-16
Score: 6 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

Vendor Solution

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: - 4.36.1F and later releases in the 4.36.x train - 4.35.6M and later releases in the 4.35.x train - 4.34.7.1M and later releases in the 4.34.x train - 4.33.9M and later releases in the 4.33.x train No hotfix is available for this issue.


Vendor Workaround

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 switch(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 switch(config-role-network-operator)#10 deny mode mgmt-api-gnsi command transport gnmi .* 256 permit command .*

Tracking

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History

Wed, 16 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 16 Sep 2026 09:15:00 +0000

Type Values Removed Values Added
Description 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 An authenticated user whose access was revoked by the new policy may retain unauthorized access to gRPC interfaces.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.
Title Security Advisory 0169
Weaknesses CWE-362
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N'}

cvssV4_0

{'score': 6, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}


Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: Arista

Published:

Updated: 2026-09-16T13:59:32.239Z

Reserved: 2026-08-12T16:45:03.511Z

Link: CVE-2026-73463

cve-icon Vulnrichment

Updated: 2026-09-16T13:59:26.563Z

cve-icon NVD

Status : Received

Published: 2026-09-16T09:17:05.300

Modified: 2026-09-16T14:17:08.863

Link: CVE-2026-73463

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-16T14:00:11Z

Weaknesses