AI agent incident

Ruflo's MCP harness carried an unauthenticated CVSS 10.0 remote code execution flaw

Reported · 2 sources · CVE-2026-59726

What happened

Ruflo, an open-source Model Context Protocol meta-harness for Claude Code and Codex, had an unauthenticated remote code execution bug tracked as CVE-2026-59726, patched in v3.16.3, that also allowed poisoning of agent memory across connected MCP servers. A related flaw reported as RufRoot was described as surviving normal patching.

Why it matters

A maximum-severity unauthenticated flaw in the layer that brokers every MCP server an agent talks to puts all of those servers within reach at once.

Sources

  1. The Hacker News Ruflo MCP Flaw Lets Unauthenticated Attackers Run Commands and Poison AI Memory
  2. Dark Reading Patch-Resistant 'RufRoot' Flaw Can Unleash Malicious AI Agent Swarms

New incidents by email

Get incidents like this one in your inbox

New AI agent incidents are covered in the briefing, with what to check on the agents you already run. At least once a week, free.

You confirm by email. Unsubscribe in one click.

Background reading

What is an MCP gateway? An explainer on the problem behind this incident.

In the tools directory

This page lists this record as a related incident, next to the products in the category and questions to ask their vendors.

Cite or correct this record

“Ruflo's MCP harness carried an unauthenticated CVSS 10.0 remote code execution flaw.” The Permission Layer AI Agent Incident Database, https://thepermissionlayer.com/incidents/ruflo-mcp-unauthenticated-rce/. Database updated October 22, 2026.

Every record traces to the dated sources above. If something here is wrong or missing, email [email protected] and it gets fixed. See this record in the full list.

The Permission Layer

Get the briefing by email

At least one email a week on AI agent identity, permissions, security and spend, written for the people who approve agent access. Five-minute read, free.

You confirm by email. Unsubscribe in one click.