Last updated: August 19, 2026 at 1:47 AM UTC
All 741 Vulnerability 286 Breach 129 Threat 319 Defense 7
Tag: mcp (10 articles)Clear

Ruflo AI agent platform exposed 233 tools through an unauthenticated MCP bridge

Noma Labs found a critical flaw in Ruflo, an open-source platform for orchestrating swarms of AI agents that acts as a harness for coding agents like Claude Code and Codex. Tracked as CVE-2026-59726 and scored 10.0, the flaw is that Ruflo's default Docker deployment exposed its Model Context Protocol bridge to the network with no authentication, offering 233 callable tools. A single unauthenticated request could invoke a shell command tool to run code in the bridge container, read AI provider API keys, steal stored conversations, and poison the platform's persistent agent memory, which can steer future outputs even after the attacker leaves. The flaw is in Ruflo, not in the coding agents.

Check
If you run Ruflo, formerly Claude Flow, update to version 3.16.3 or later, and confirm its MCP bridge is not bound to a network-reachable interface.
Affected
Teams running Ruflo before 3.16.3 with the default Docker deployment (CVE-2026-59726); an unauthenticated network attacker can run commands, steal AI provider keys and conversations, and poison persistent agent memory.
Fix
Update Ruflo, rotate AI provider API keys, rebuild affected containers from clean images, inspect the agent memory store for unfamiliar instructions, and keep MCP bridges bound to loopback and behind authentication.

Hidden pull request comments can hijack AI agents via Microsoft's DevOps MCP server

Offensive security firm Manifold Security detailed a confused deputy flaw in Microsoft's official Azure DevOps MCP server, which lets AI agents read and operate Azure DevOps on a user's behalf across pull requests, pipelines, wikis, and work items, using that user's own permissions. One of the server's tools returns pull request descriptions without the prompt injection guardrail Microsoft had already applied to other tools. Because descriptions accept Markdown, an attacker can bury instructions in an HTML comment: the web interface renders it as nothing, so a reviewer sees an ordinary change, while the REST API returns the text verbatim and hands it straight to the agent.

Check
Check whether AI agents in your environment use the Azure DevOps MCP server, and review what permissions those agents inherit, since content written by others becomes instructions the agent may act on.
Affected
Teams running AI agents against Azure DevOps through Microsoft's MCP server; a pull request description containing a hidden HTML comment can steer the agent, which acts with the requesting user's full permissions.
Fix
Treat repository and ticket content reaching an agent as untrusted input, scope MCP server permissions well below the user's own, require human approval for write actions, and monitor agent tool calls.

Poisoned web page could rewrite AWS Kiro's config file and run code

Researchers at Intezer showed that a poisoned web page could take over AWS Kiro, an AI coding tool, by getting the agent to rewrite the file that governs what it is allowed to run. A prompt injection in fetched content drops custom code into the MCP settings file, which executes the moment the file is saved. The same write to execution path was demonstrated on Kiro's release day in July 2025 by another researcher, who also flagged writing to a Visual Studio Code settings file to allowlist shell commands. AWS added an approval prompt, but only in supervised mode, leaving the default autonomous mode writing the file unprompted.

Check
If you use AWS Kiro or similar agentic coding tools, check which mode they run by default and whether the agent can write its own MCP or editor configuration files without approval.
Affected
Developers running AWS Kiro in its default autonomous mode; content fetched from a web page can inject instructions that rewrite the agent's MCP settings file, and saving that file executes attacker-supplied code.
Fix
Require approval for agent writes to configuration files in every mode, keep those files outside what the agent can modify, and treat fetched web content as untrusted rather than trusting mode settings.

FakeGit floods GitHub with fake AI skills and MCP servers that drop malware

Researchers at Island uncovered FakeGit, a campaign running roughly 7,600 malicious GitHub repositories from about 6,600 lookalike developer profiles, of which more than 800 pose as AI skills or Model Context Protocol servers. The fake projects borrow the names and workflows of familiar tools, covering Gmail and WhatsApp integrations through to Databricks, Jenkins, and Docker tooling, and their convincing README files walk a user or an agent from routine setup into downloading a malicious ZIP. That triggers a loader chain ending in SmartLoader, which establishes persistence and pulls further payloads such as the StealC infostealer.

Check
Treat AI skills and MCP servers on GitHub as untrusted code: verify the publishing account and project history before installing, and be wary of setup steps that download a ZIP release.
Affected
Developers and AI agents installing skills or MCP servers from GitHub; more than 800 fake repositories impersonate familiar tools, and following their setup instructions leads to SmartLoader and the StealC infostealer.
Fix
Install AI skills and MCP servers only from verified publishers, review repository history and profile age, scan packages before use, and restrict what credentials and systems an installed MCP server can reach.

Microsoft warns poisoned MCP tool descriptions can make AI agents leak data

Microsoft is warning that attackers can hijack AI agents through poisoned tool descriptions, the plain-text notes that tell an agent what a tool does. Because agents connect to systems through the Model Context Protocol and read these descriptions to decide how to act, an attacker who updates a trusted third-party tool can bury a hidden instruction in its description, telling the agent to quietly collect and exfiltrate data on its next task. Many setups pick up description changes without re-approval, so the poisoned version goes live silently. Each step the agent takes looks legitimate and runs with the user's own permissions, so no alarm fires.

Check
Inventory the MCP tools and servers your AI agents can use, especially third-party ones, and check whether your setup re-approves or reviews tool descriptions when they change rather than trusting updates automatically.
Affected
Organizations running AI agents connected to third-party MCP tools without re-approval on description changes; a poisoned description can redirect the agent to exfiltrate data using the user's own permissions, invisibly.
Fix
Require review when tool descriptions change, pin and verify tool sources, scope agents with least privilege, log every tool invocation at the infrastructure layer, and gate sensitive actions behind human approval.

Amazon Q Developer flaw let a malicious repo steal a developer's cloud keys

Wiz Research found a high-severity flaw in Amazon Q Developer, Amazon's AI coding assistant, that let a malicious code repository run commands and steal a developer's cloud credentials simply by being opened. The bug (CVE-2026-12957) lay in how Amazon Q handled Model Context Protocol servers: it read an MCP configuration file from the open workspace and automatically launched the servers it defined. Because those servers run as local processes that inherit the developer's full environment, a single config file committed to a repo could reach AWS keys, cloud tokens, API secrets, and SSH agent sockets, turning a git clone into a full compromise. Amazon has patched the issue and published an advisory.

Check
Confirm Amazon Q Developer is updated to the patched version, and review whether developers open untrusted repositories in AI coding assistants that can auto-launch Model Context Protocol servers from in-repo configuration files.
Affected
Developers using vulnerable versions of Amazon Q Developer (CVE-2026-12957) who open untrusted repositories; a malicious MCP configuration file could run commands and steal cloud credentials from the developer's environment.
Fix
Update Amazon Q Developer, treat opening a repository in an AI assistant as running its code, disable automatic MCP server launching where possible, and isolate untrusted repos without real credentials.

Agentjacking hijacks AI coding agents via fake Sentry error reports

Researchers at Tenet Security have disclosed Agentjacking, a new attack that turns AI coding assistants like Claude Code, Cursor, and Codex into tools for running an attacker's code on a developer's machine. The trick abuses Sentry, a widely used error-tracking service: anyone can submit a fake error event using a project's DSN, a public write-only key embedded in website code, and the AI agent, fetching that event through Sentry's MCP integration, cannot tell the malicious instructions from real diagnostics and runs them with the developer's privileges. No phishing, malware, or server breach is needed, and it bypasses traditional controls because every step is technically authorized. Tenet found 2,388 exposed organizations.

Check
Inventory developers using AI coding agents connected to Sentry or other MCP integrations that surface external data, and check whether your Sentry DSNs are exposed in frontend code or repositories.
Affected
Development teams using MCP-connected AI coding agents (Claude Code, Cursor, Codex) alongside Sentry; any project whose public DSN lets attackers inject error events that the agent treats as trusted instructions.
Fix
Run AI coding agents with least privilege in sandboxes, require human approval before they execute commands, treat all MCP tool output as untrusted, and limit which integrations feed agents external data.

'Shai-Hulud: The Third Coming' worm pivots from Checkmarx KICS compromise into Bitwarden CLI, stealing SSH keys, cloud secrets, and MCP configs for AI coding tools

TeamPCP's self-propagating supply-chain worm is back in its third iteration, branded 'Shai-Hulud: The Third Coming' in hard-coded strings across the malware. On April 22, Socket reported Checkmarx's official KICS Docker images and a KICS VS Code / Open VSX extension had been trojanized. Bitwarden's own clients repo runs a Checkmarx scan on every pull request via a pull_request_target workflow that holds id-token: write and fetches credentials from Azure Key Vault, so when the poisoned scanner executed it harvested GitHub OIDC and Azure tokens. At 17:57 ET the same day, attackers used those tokens to push a modified publish-cli.yml to the Bitwarden repo and publish a malicious @bitwarden/cli version 2026.4.0 to npm. The package remained live for 93 minutes until Bitwarden pulled it at 19:30 ET. The payload: a 10MB obfuscated credential harvester that grabs SSH keys, cloud provider credentials, npm publish tokens, GitHub tokens, and - new in this variant - MCP (Model Context Protocol) configuration files used by Claude Code, Cursor, and similar AI coding tools. It then self-propagates by republishing into every npm package the victim can modify and uploads encrypted stolen secrets to public GitHub repositories under Dune-themed names. The worm has a Russian-locale kill switch (exits if LC_ALL/LANG starts with 'ru').

Check
Immediately check every CI/CD runner, developer laptop, and container that pulled Checkmarx KICS Docker images, the KICS GitHub Action, or @bitwarden/cli between March 23 and April 23, and rotate every credential that was ever present on those machines.
Affected
Confirmed malicious artifacts per Socket: @bitwarden/cli 2026.4.0 on npm (live 21:57 to 23:30 UTC on April 22, a 93 minute window); compromised Checkmarx KICS Docker images and GitHub Actions (first compromised March 23, re-compromised April 22); two Checkmarx-published Visual Studio Code and Open VSX extensions. Any npm package subsequently republished by a victim whose npm token this worm captured is also potentially malicious.
Fix
Remove the listed versions from all developer environments, CI runners, and private mirrors. Rotate every credential the worm would have seen: GitHub PATs and OIDC tokens, npm publish tokens, cloud provider keys (AWS/GCP/Azure), SSH keys, Azure Key Vault secrets, container registry creds, and MCP config files for AI coding tools - assume every credential stored in ~/.config, ~/.ssh, or exported to CI env is burned. Audit bitwarden/clients commit history for changes to publish-cli.yml and similar pipeline files around April 22. Search public GitHub for repositories named after Dune terms (beautifulcastle-* pattern) to find whether your stolen data has been published. Tighten pull_request_target triggers on security scanners - they should not have id-token: write permission.

Anthropic MCP STDIO design flaw exposes 200,000+ AI servers to RCE - 14 CVEs assigned, Anthropic calls it 'expected behavior' (backfill from April 15)

Backfill from April 15: OX Security disclosed an architectural flaw in the official Model Context Protocol SDKs (Python, TypeScript, Java, Rust) that lets attacker-controlled JSON config trigger arbitrary OS commands via the STDIO transport. Roughly 200,000 publicly reachable MCP servers and 150 million SDK downloads inherit the issue. OX has tied 14 CVEs to the same root cause across LiteLLM (patched), Bisheng (patched), Windsurf (zero-click RCE in Cursor-style IDEs, still reported), Flowise, LangFlow, GPT Researcher, Agent Zero, and DocsGPT. Anthropic declined to patch the protocol, calling the behavior 'expected.'

Check
Audit every MCP server installed in Claude Code, Cursor, and other AI dev tools, remove any whose origin you don't recognize, and treat MCP configs as executable code.
Affected
Any tool or service running an Anthropic-SDK MCP server with STDIO transport, especially when add/configure flow is exposed to user input or marketplaces. Confirmed-affected: LiteLLM, LangChain, LangFlow, Flowise, LettaAI, LangBot, DocsGPT, Bisheng, Windsurf, Cursor IDE workflows, GPT Researcher, plus any private MCP server built on the official SDK without input sanitization.
Fix
Patch downstream tools to fixed versions (LiteLLM, Bisheng, Cursor). Block public internet access to services that host MCP add/configure UIs. Treat all external MCP configuration input as untrusted; never let raw user input reach StdioServerParameters. Run MCP services in sandboxes with no production-secret access. Install MCP servers only from verified sources and pin to specific commits.

Nginx UI authentication bypass actively exploited - one unauthenticated request gives attackers full server takeover via MCP endpoint (CVE-2026-33032)

A CVSS 9.8 authentication bypass in nginx-ui, the popular open-source web management interface for Nginx servers, is being actively exploited in the wild. The flaw, codenamed MCPwn by Pluto Security, exists because the /mcp_message endpoint added for Model Context Protocol (AI integration) support only checks IP whitelisting - and the default whitelist is empty, meaning it allows all connections. One unauthenticated HTTP POST request lets an attacker invoke all MCP tools: rewrite Nginx config files, reload the server, intercept all traffic, and harvest admin credentials. Attackers chain it with CVE-2026-27944 (exposed encryption keys via the backup API) to extract the node_secret needed for full MCP access. Recorded Future flagged active exploitation and assigned a risk score of 94/100. Shodan shows 2,600 publicly exposed instances, mostly in China, the US, Indonesia, and Germany. Pluto Security's key lesson: AI integration endpoints expose the same capabilities as the core application but often skip its security controls.

Check
Check if you or any managed clients run nginx-ui (web-based Nginx management dashboard). If MCP support is enabled, this is urgent - you're likely exposed.
Affected
nginx-ui versions 2.3.5 and earlier with MCP support enabled. The tool has 11,000+ GitHub stars and 430,000 Docker pulls. Any instance reachable from the network is exploitable without credentials.
Fix
Update nginx-ui to version 2.3.6 immediately (2.3.4 was the first fix, 2.3.6 is current). If you can't patch: restrict network access to the nginx-ui management interface to trusted IPs only. Add authentication middleware to the /mcp_message endpoint. As defense-in-depth, audit all MCP-integrated tools in your environment - this class of flaw (AI integration endpoints skipping auth) will appear in other products.