Mandia’s Armadin Hits $255.5M Series B at >$2.5B for Agentic Offense

Correction, October 14, 2026: We clarified that the $189.9 million announced at Armadin’s March launch was combined seed and Series A funding. The earlier $24 million seed should not be added again to that amount.

Offensive security just got another nine-figure check.

Armadin, the AI-native cybersecurity company led by Mandiant founder Kevin Mandia, announced a $255.5 million Series B co-led by Andreessen Horowitz (a16z) and Accel that values the company at over $2.5 billion. Per the company release on PR Newswire (October 1, 06:00 ET) and SecurityWeek, the round brings total funding to about $445 million roughly seven months after public launch. New money: Bain Capital Ventures and Redpoint. Returning: 8VC, Ballistic Ventures, GV (Google Ventures in the release), In-Q-Tel, Kleiner Perkins, and Menlo Ventures. SecurityWeek’s March launch report describes $189.9 million in combined seed and Series A funding and notes a previously announced $24 million seed. The seed is part of the launch funding, not an additional amount to add to it.

What the money buys#

Product frame, company-stated: autonomous swarms of specialized agents that chain individually low-severity findings into validated kill chains — from unauthenticated perimeter RCE through lateral movement to cloud compromise — for Fortune 500 and government customers already running agentic attack campaigns in production. Thesis: frontier models compress vulnerability-to-exploit time; periodic pen tests and isolated scanner scores cannot keep pace. Proceeds: scale the agentic platform, research and training, and go-to-market.

Investor lines in the release lean hard on the dual-use pitch — Accel’s Ping Li: “best defense is a great offense powered by AI”; a16z’s David George calls Armadin a defining security company of the AI era. Those are press-release quotes, not diligence.

Exercise metrics — company-reported#

SecurityWeek recounts an August live exercise with TENEX.ai: 1,300 attacks, about 26,000 agents, roughly 17 million offensive actions against more than 25,000 services, producing 238 findings (98 “significant”) chained into 38 validated attack paths, under a safety-model control layer and without privileged credentials or source access — all company-described. Treat as demonstration narrative, not an independent audit.

Co-founders named by SecurityWeek: CTO Travis Lanham, chief offensive security officer Evan Peña, chief architect David Slater.

Limits#

• Financing figures ($255.5M, >$2.5B valuation, ~$445M total, co-leads, investor list) rest on Armadin’s PR Newswire release, corroborated by SecurityWeek.
• The $189.9M combined seed and Series A funding and earlier $24M seed are reported by SecurityWeek’s March launch article; the seed is not added again to the combined amount.
• Production F500/gov deployment and TENEX exercise metrics are company-reported.

Sources#

• PR Newswire / Armadin: Armadin Raises $255.5 Million Series B to Scale Effective Autonomous Security (October 1, 2026)
• SecurityWeek: Kevin Mandia’s Armadin Raises $255 Million at $2.5 Billion Valuation (October 1, 2026)
• SecurityWeek: Kevin Mandia’s Armadin Launches With $190 Million in Funding (March 10, 2026)
• PR Newswire / Armadin: Armadin and TENEX.ai Describe a Controlled Live AI Cyberattack (August 3, 2026)