Arista EOS up to 4.36.1F OSPFv3 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. Affected by this vulnerability is an unknown functionality of the component OSPFv3. Performing a manipulation results in input validation. This vulnerability was named CVE-2026-73438. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Arista EOS up to 4.32.x/4.33.9M/4.34.7M/4.35.5M/4.36.1F. This affects some unknown functionality of the component OSPFv3. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as 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. This is going to have an impact on availability. The summary by CVE is:

On affected platforms running Arista EOS with Open Shortest Path First version 3 (OSPFv3) configured, an unauthenticated attacker on the same OSPFv3 broadcast domain can send a specially crafted set of packets that can cause the Ospf3 agent to restart unexpectedly. The crash results in the loss of all OSPFv3 adjacencies on the affected device and may disrupt routing across the broader OSPF domain until the agent recovers. This issue was reported externally by Dravanet Inc., and Arista is not aware of any malicious exploitation of this vulnerability in customer networks.

It is possible to read the advisory at arista.com. This vulnerability is uniquely identified as CVE-2026-73438 since 08/12/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 4.33.0F eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion