Arista EOS up to 4.36.0.1F gNMI improper authorization

Summaryinfo

A vulnerability marked as critical has been reported in Arista EOS up to 4.32.x/4.33.8M/4.34.7M/4.35.5M/4.36.0.1F. Affected is an unknown function of the component gNMI. Performing a manipulation results in improper authorization. This vulnerability is identified as CVE-2026-19640. The attack can be initiated remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Arista EOS up to 4.32.x/4.33.8M/4.34.7M/4.35.5M/4.36.0.1F. It has been classified as critical. This affects an unknown code of the component gNMI. The manipulation with an unknown input leads to a improper authorization vulnerability. CWE is classifying the issue as CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

On affected platforms running Arista EOS, an authenticated user with access to the gNMI (gRPC Network Management Interface) may receive incorrect authorization results, potentially allowing access beyond their currently assigned permissions. This issue was discovered internally by Arista and the company is not aware of any malicious uses of this issue in customer networks.

It is possible to read the advisory at arista.com. This vulnerability is uniquely identified as CVE-2026-19640 since 08/12/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1548.002 according to MITRE ATT&CK.

Upgrading to version 4.33.0F eliminates this vulnerability.

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Productinfo

Vendor

• Arista

Name

• EOS

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 4.17
• 4.18
• 4.19
• 4.20
• 4.21
• 4.22
• 4.23
• 4.24
• 4.25
• 4.26
• 4.27
• 4.28
• 4.29
• 4.30
• 4.31
• 4.32
• 4.33.8M
• 4.34.7M
• 4.35.5M
• 4.36.0.1F

License

• commercial

CPE 2.3info

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CPE 2.2info

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