Arista EOS up to 4.33.8M/4.34.6M/4.35.5M/4.36.0.1F gNSI Pathz Policy Enforcement privileges management

Summaryinfo

A vulnerability was found in Arista EOS up to 4.33.8M/4.34.6M/4.35.5M/4.36.0.1F. It has been rated as very critical. This affects an unknown function of the component gNSI Pathz Policy Enforcement. The manipulation leads to privileges management. This vulnerability is referenced as CVE-2026-73439. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in Arista EOS up to 4.33.8M/4.34.6M/4.35.5M/4.36.0.1F and classified as very critical. This issue affects an unknown function of the component gNSI Pathz Policy Enforcement. The manipulation with an unknown input leads to a privileges management vulnerability. Using CWE to declare the problem leads to CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at arista.com. The identification of this vulnerability is CVE-2026-73439 since 08/12/2026. The exploitation is known to be easy. The attack may be initiated remotely. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/17/2026). MITRE ATT&CK project uses the attack technique T1068 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at EUVD (EUVD-2026-80252) and CERT Bund (WID-SEC-2026-3287). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Arista EOS

Productinfo

Vendor

• Arista

Name

• EOS

Version

• 4.33.8M
• 4.34.6M
• 4.35.5M
• 4.36.0.1F

License

• commercial

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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