On May 21, 2026, Composio disclosed unauthorized access to internal systems. According to the company's own bulletin, an attacker used LLM-assisted exploit patterns to compromise an internal agentic tool used to monitor infrastructure and report connector failures, then moved through automated remediation systems to escalate privileges and ultimately expose a subset of connected credentials — Composio reported roughly 0.3% of total active connections affected, with GitHub (around 5,001 connections) the largest single category, alongside smaller numbers across Gmail, Jira, HubSpot, Linear, Notion, Slack, and others.

What makes this worth more than a footnote is the nature of the attack: a company building infrastructure for AI agents was compromised through a path that ran directly through its own internal agentic tooling. Composio's response was substantive rather than cosmetic — all affected GitHub tokens were revoked as a precaution, affected users were notified, credentials and encryption keys were rotated, and the company published a technical breakdown of a rebuilt execution architecture in September: requests now flow through authentication, a policy check, token resolution, and an isolated execution container before reaching a third-party API, with credentials decrypted only momentarily inside that isolated runtime — never returned to the calling application or exposed to the model's context.

A separate reliability incident in April 2026 is worth noting too, if only because it happened in the same window: a stalled cleanup job let a trigger-processing database table grow unbounded, cascading into roughly 36 hours of webhook trigger outages affecting an estimated 700 customers. Neither incident alone would necessarily be disqualifying — most infrastructure companies have a bad month eventually — but for a product whose entire value proposition is holding the keys to an agent's real-world actions, this year's incident history is material context, not a side note, for anyone connecting production credentials.

The most useful lens for Composio isn't "how many integrations does it have" — competitors can build long integration lists too. The actual differentiator is the identity-and-execution layer underneath: who is this agent acting for, which account, which action, is it allowed, execute, log. That's the part that's genuinely hard to build production-grade, and it's why companies like AWS, Glean, and Browser Use reportedly use Composio behind their own agent products rather than building this layer themselves.

It's also exactly why this review can't treat the May 2026 incident as a footnote. A tool-integration company getting breached is bad. An agent-infrastructure company getting breached through its own internal agentic tooling is a preview of a threat model the entire industry is going to have to take seriously — attackers using LLM-assisted techniques against the automation layers companies build to manage their own systems. Composio's public, detailed response to that incident is genuinely better than what most vendors do after a breach, and it should factor into the evaluation — but it doesn't erase the fact that it happened.

The other honest caveat sits in Composio's own benchmark data. A company confident in its execution layer publishing a benchmark where several stateful, multi-step tasks score under 50% — some at 0% — is a credibly humble move, and it's a useful reminder that Composio makes execution possible; it doesn't make the underlying model reliable. If an agent picks the wrong tool, mis-fills a parameter, or loses track of state across steps, Composio's infrastructure won't rescue that on its own.

Taken together: this is a serious, well-engineered answer to a real problem, priced reasonably for teams that need it, with a security and reliability history in 2026 that demands eyes-open evaluation rather than a blanket recommendation. That combination — genuinely valuable architecture, genuinely material incident history — is precisely why this scores as competent-but-compromised rather than an easy top-tier pick.