Arista EOS up to 4.36.1F state issue

Summaryinfo

A vulnerability was found in Arista EOS up to 4.32.x/4.33.9M/4.34.7.1M/4.35.5M/4.36.1F. It has been classified as critical. The affected element is an unknown function. The manipulation leads to state issue. This vulnerability is traded as CVE-2026-73450. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Arista EOS up to 4.32.x/4.33.9M/4.34.7.1M/4.35.5M/4.36.1F. This issue affects an unknown code block. The manipulation with an unknown input leads to a state issue vulnerability. Using CWE to declare the problem leads to CWE-371. Impacted is integrity, and availability. The summary by CVE is:

On affected platforms running Arista EOS with MLAG Dual Primary Detection configured, an unauthenticated attacker with access to the Dual Primary Detection network segment can send specially crafted packets to interfere with the dual-primary state. If the MLAG primary switch fails while these packets are present, the secondary switch incorrectly concludes it is in a dual-primary condition and err-disables its interfaces, leading to a traffic interruption.

The advisory is shared at arista.com. The identification of this vulnerability is CVE-2026-73450 since 08/12/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available.

Upgrading to version 4.33.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-80083). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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
• 4.33.9M
• 4.34.7.1M
• 4.35.5M
• 4.36.1F

License

• commercial

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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