Linux Kernel Vulnerability in Open vSwitch Related to Nested Action Attributes

CVE-2026-64531

What is CVE-2026-64531?

A vulnerability in Open vSwitch allows for oversized nested action attributes which can disrupt the intended processing of generated actions. This occurs when the total size of flow actions exceeds 64 KiB due to a recent modification that lifted previous restrictions. If an oversized action is not properly validated, it can lead to a structural misalignment of the action stream, enabling potentially malicious interpretations of subsequent actions. This could result in unpredictable behavior or exploitation opportunities within the network. It is essential to mitigate this issue through validation checks for nested action closures, ensuring that generated actions conform to expected size limits.

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