Vanta signs agreement to acquire AI agent security company Pillar Security

On 9 November 2026, compliance automation company Vanta announced that it has signed a definitive agreement to acquire Pillar Security, an AI security platform that it says protects AI agents across their lifecycle. Vanta says Pillar’s adversarial testing and runtime protection will be added to its Trust Platform to connect a company’s written AI policies to controls enforced while agents run. Vanta’s announcement does not state a price or an expected closing date.

What Vanta says Pillar Security will add to its Trust Platform

Pillar Security was founded in 2023 by Ziv Karliner and Dor Sarig. Vanta says it will integrate Pillar’s capabilities into its platform throughout 2027, on this schedule:

• AI inventory (January 2027): mapping the AI applications, models, agents and MCP servers in use across an organization.
• Runtime monitoring and detection (January 2027): flagging suspicious activity and guardrail violations.
• Red-teaming (spring 2027): adversarial tests tailored to a customer’s business.
• Runtime enforcement (summer 2027): blocking unauthorized agent actions in real time.

Vanta’s chief executive, Christina Cacioppo, said in the release that “a policy document doesn’t get you there.” Vanta says it has more than 20,000 customers and that Pillar is its third acquisition, after Trustpage (January 2023) and Riskey (July 2025). Calcalist, an Israeli business publication, reported that the price is about USD 150 million in cash and shares and that Pillar had raised about USD 9 million since it was founded; Vanta’s release does not state either figure.

Why the Vanta and Pillar deal matters for AI assurance buyers

Vanta sells compliance automation: software that collects evidence for security and privacy frameworks and audits. Pillar’s work falls in two categories described on the AI assurance Learn page, evaluation and red-teaming, and runtime guardrails. If completed, the deal would put pre-deployment testing and runtime control of AI agents inside a platform that companies already use to produce audit and compliance evidence, a link Vanta frames as giving customers, regulators and auditors proof that a company’s AI “does what it says on the tin.”

It comes six days after CrowdStrike announced its intent to acquire Fiddler and Dreadnode (News). Among the acquisitions tracked on this site, the buyers have been security, data and infrastructure platforms, model developers and AI application companies; Vanta is the first compliance automation vendor among them. The consolidation is tracked on the AI Risk Timeline.

What Vanta has not yet said about the Pillar deal

The announcement does not say when the acquisition is expected to close, whether Pillar will remain available as a standalone product, or what will happen to existing Pillar customer contracts. The 2027 dates are Vanta’s stated plans; the release does not say how they depend on the deal closing.