Infisical raises a $40M Series B at a $600M valuation, led by Elad Gil, to keep AI agents away from credentials

TLDR

• Infisical raised a $40M Series B at a $600M valuation, led by existing investor Elad Gil.¹
• The secrets-management firm is selling Agent Vault, which lets AI agents reach systems without holding credentials.¹
• The company says it has long been cash-flow positive and did not need to raise.²

Infisical, a San Francisco security software company, announced on 27 October 2026 a $40 million Series B at a $600 million valuation, according to its release.¹ Elad Gil led, as he did the Series A, and the release names Gradient and Y Combinator among the other investors.¹ CEO Vlad Matsiiako's blog post adds Gallery Ventures, Pace Capital and Dynamic Capital, and says Gil is "doubling down" while Y Combinator and Gradient are "tripling down".² Fortune named a Dynamic Fund among the Series A investors; the sources do not say whether that is the same firm as Dynamic Capital, or whether Gallery Ventures and Pace Capital are new.³

Infisical sells software to secure credentials, manage access to critical systems and keep digital certificates renewed.¹ It says it serves more than 1,300 customers and 300,000 developers, secures 10 billion secrets a day, and that its open-source project has more than 30,000 GitHub stars.¹ The release lists Airbus, Volkswagen, Hugging Face, OpenRouter, Lucid, First American Financial, Wise and Clay as customers, and the blog adds LG and the US Government.¹² No source ties Infisical to defence work. The pitch for this round is Agent Vault, which lets a company set what each AI agent can reach so that the agent never holds the password or API key, and so cannot leak it in an attack or pass it to an LLM provider.¹

Matsiiako writes that Infisical has been cash-flow positive for a long time and has more money in the bank than it has ever raised, so the round was a choice.² The money is for secrets, certificate and privileged-access management, more work on Agent Vault, and hiring for more than 100 roles.² No revenue figure appears in this round's sources. At the Series A in June 2025, Fortune reported a $16 million raise by a company founded in 2022 by Matsiiako, Tony Dang and Maidul Islam, which said it was cash-flow positive and had grown revenue 20 times in a year, and declined to give revenue.³ Fortune also set the market backdrop: IBM had completed its $6.4 billion purchase of the incumbent HashiCorp in February 2025.³

On the lead investor, Gil told Fortune in 2025 that he looks for "positive gravity" in a market and that Infisical had "really clear product-market fit".³ The sources do not describe Gil's other security holdings. Gradient, which says it partnered with Infisical in early 2023, wrote in June 2025 that the company then secured over 500 million secrets a day and had more than 17,000 GitHub stars.⁴ Against the 10 billion secrets and 30,000 stars claimed now, that is the growth the new round is priced on, though all of these are company figures.¹⁴

Dealroom treats the deal as part of a wave in securing AI-agent identity and access. It cites Oak's $60 million and NewCore's $66 million raises and says cybersecurity funding reached $6.8 billion in the third quarter of 2026; those are Dealroom's figures and were not checked here.⁵ It also notes the step up from the $16 million Series A, which Gil also led.⁵

Why it matters: a profitable open-source secrets firm is raising at $600 million on the argument that AI agents need controlled access to company systems, a pitch that leans on Agent Vault, for which the sources give no adoption figures.¹² Watch whether Infisical discloses revenue or Agent Vault customers.