Arista EOS up to 4.36.1F OSPFv2 input validation

Summaryinfo

A vulnerability identified as critical has been detected in Arista EOS up to 4.32.x/4.33.9M/4.34.7M/4.35.5M/4.36.1F. This affects an unknown function of the component OSPFv2. This manipulation causes input validation. The identification of this vulnerability is CVE-2026-73435. It is possible to initiate the attack remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Arista EOS up to 4.32.x/4.33.9M/4.34.7M/4.35.5M/4.36.1F and classified as critical. Affected by this vulnerability is some unknown functionality of the component OSPFv2. The manipulation with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect availability. The summary by CVE is:

On affected platforms running Arista EOS with Open Shortest Path First version 2 (OSPFv2) configured, a specially crafted OSPFv2 packet from an unauthenticated attacker on the same broadcast segment, with OSPFv2 authentication configured can cause adjacency flapping and packet loss. The disruption can affect routing across the broader OSPF domain.

The advisory is shared at arista.com. This vulnerability is known as CVE-2026-73435 since 08/12/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available.

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
• 4.33.9M
• 4.34.7M
• 4.35.5M
• 4.36.1F

License

• commercial

CPE 2.3info

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CPE 2.2info

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Entryinfo

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