Cybersecurity M&A Roundup: Proofpoint Agrees $6.3bn Varonis Acquisitio

A number of important merger and acquisition (M&A) announcements were made in October 2026, with the need to enhance AI security a recurring theme.

The biggest headline deal of the month was Proofpoint entering into a definitive agreement to buy AI security specialist Varonis for $6.3bn.

Anthropic to Acquire AI Security Startup Opaque Systems AI frontier firm Anthropic has agreed to acquire AI security company Opaque Systems in a deal announced on October 13.

Proofpoint Agrees $6.3bn Varonis Transaction On October 15, Proofpoint announced it had entered into a definitive agreement to acquire Varonis for $6.3bn.

AISLE’s three founders will take leadership roles in Cohere spanning cybersecurity, corporate security, AI security research and frontier model development once the transaction closes.