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eSentire Appoints Cybersecurity Industry Veteran James C. Foster as Chief Executive Officer

Proven CEO Brings 25+ Years of AI and Cybersecurity Leadership to the Authority in
AI-Powered Managed Detection and Response

March 19, 2026 | 5 MINS READ

WATERLOO, Ontario, March 19, 2026 – eSentire, The Authority in AI-powered Managed Detection and Response (MDR), today announced the appointment of James C. Foster as Chief Executive Officer. Foster assumes the role, previously held by Kerry Bailey, who is retiring after leading the company through a period of sustained growth. Foster is a globally recognized cybersecurity entrepreneur and executive who has spent more than two decades building and scaling market-defining cybersecurity companies. His appointment marks an important milestone in eSentire’s continued mission to deliver world-class managed attack, detection and response services while protecting organizations from increasingly sophisticated cyberthreats.

Foster, who is best known as the founder and former Chairman and CEO of ZeroFox, where he built and successfully took public the industry’s leading external cybersecurity platform. During his tenure, ZeroFox achieved more than 30 consecutive quarters of ARR growth, expanded across four continents, completed five strategic acquisitions, and grew into a multi-hundred-million-dollar global enterprise protecting thousands of organizations worldwide. Foster brings more than 25 years of extensive expertise in artificial intelligence, cybersecurity, and company building to eSentire.

Earlier in his career, Foster founded Ciphent, which quickly became one of the fastest-growing cybersecurity companies in the United States, serving more than 1,000 enterprise customers including 43 of the Fortune 100 before merging with Accuvant (now Optiv). He subsequently helped scale Accuvant’s platform during a period of rapid growth that drove the business toward $500 million in annual revenue.

His career also includes foundational roles scaling companies as an Operating Partner at NightDragon, a leading cybersecurity venture capital and growth firm, as well as at Guardent (acquired by VeriSign), Foundstone (acquired by McAfee),Ciphent/Accuvant (now Optiv), and IronCircle (acquired by QuickStart), in addition to his service in supporting U.S. national security at the Department of Defense. He is a widely published author of more than a dozen books on advanced threats, cyberattacks, and defense strategies.

“eSentire has built something truly exceptional — a 25-year track record of growth and protecting many of the world’s most targeted organizations, a world-class team of threat hunters and security analysts, and an AI-powered platform in Atlas that is unmatched in the MDR space,” said Foster. “The threat landscape is evolving faster than ever, and organizations need a cybersecurity partner who can meet that pace with both agentic and human expertise. I am honored to work alongside this outstanding team and ensure that eSentire is delivering on our mission: hunting, investigating, and stopping cyber threats before they become business-disrupting events.”

Founded in 2001, eSentire protects the critical data and applications of more than 2,000+ organizations in over 80 countries across 35 industries. The company’s AI-powered Atlas Security Operations Platform combines multi-agent AI, 24/7 threat hunting, and proven security operations to deliver outcomes-driven protection at scale. 

“It has been an incredible privilege to lead eSentire through a period of tremendous growth, and I could not be more confident in the future of this company,” said Kerry Bailey, outgoing eSentire CEO. “Foster brings exceptional vision, deep industry expertise, and a proven track record of building world-class security organizations. eSentire has never been better positioned — with the team, the technology, and the mission to redefine what Managed Detection and Response means for organizations around the world. I have every confidence that under Foster's leadership, eSentire will continue to raise the bar for our customers, our partners, and the industry as a whole. I'm proud of what we have built together, and I'm excited to watch what comes next." 

“eSentire has built a strong reputation as a trusted partner delivering world-class managed detection and response to organizations facing an increasingly complex threat landscape,” said John Becker, Chairman of eSentire. “As the market rapidly evolves toward more proactive, AI-driven and intelligence led security operations, we believe Foster is the ideal leader to guide eSentire into its next chapter. His experience building and scaling innovative cybersecurity platforms, combined with his deep understanding of modern adversaries, will help accelerate our vision of delivering continuous protection and measurable security outcomes for customers worldwide.” 

“Foster is a proven cybersecurity leader with a rare track record of building and scaling category-defining security companies,” said Lauren Zletz, Managing Director at Warburg Pincus and a member of the eSentire Board of Directors. “His experience taking platforms from early growth to global scale, combined with his deep understanding of the evolving threat landscape, makes him exceptionally well suited to lead eSentire in its next phase. We believe Foster’s leadership will accelerate the company’s innovation, strengthen its position as a trusted partner for organizations worldwide, and drive long-term value for customers and shareholders alike.”

Foster holds advanced education from Capitol Technology University and The Wharton School, University of Pennsylvania. He is a recognized thought leader in the cybersecurity community and a frequent speaker at industry forums on AI, cyber workforce development, and enterprise security strategy.

About eSentire 
eSentire is the Authority in AI-powered Managed Detection and Response Services, protecting the critical data and applications of 2,000+ organizations in 80+ countries from known and unknown cyber threats. Founded in 2001, the company’s mission is to hunt, investigate, and stop cyber threats before they become business-disrupting events. Powered by the Atlas Security Operations Platform and a 24/7 Security Operations Center, staffed by elite threat hunters and cyber analysts, eSentire delivers the most resilient, outcomes-driven security protection in the industry. For more information, visit www.esentire.com and follow @eSentire.