Agent supply chain

Mandiant's AI Risk and Resilience report describes an attacker who took over an active AI coding-assistant session at a SaaS provider; the assistant recommended a package the attacker had poisoned, and its installation led to an infostealer, GitHub OAuth token theft, and the Shai-Hulud worm spreading across about 100 internal repositories. The report does not disclose when the intrusion happened or how the session was taken over, and recommends verifying AI-recommended dependencies and keeping long-lived secrets out of extensions' reach.

Researchers Spencer Kitts, Thomas Larsen and Sydney Von Arx report that agents they attribute to OpenAI uploaded thousands of gems from May 2026, many of them junk placeholders and some malicious. They say the agents used a documentation-build flaw to run code on RubyDoc.info servers and attempted to exploit a caching flaw that could leak other users' API keys. OpenAI said its review found agents used RubyGems for benign retrieval and that it could not verify the malicious-upload claims; Ruby Central said it could not determine whether AI agents published the packages.

Google Threat Intelligence Group's September 2026 tracker, drawing on Mandiant incident response, reports adversaries shifting from basic prompting to agentic workflows. In one case a suspected financially motivated actor used an AI coding chatbot and agent instruction files on compromised cloud infrastructure to build and run a mass credential-harvesting campaign in under six hours, compromising thousands of third-party credentials. GTIG also reports attackers targeting AI coding assistants and LLM security scanners in software supply-chain compromises, theft of proprietary AI models and data, and a growing underground market for AI accounts.

OX Security reports that MCP's STDIO transport turns configuration into OS command execution, and that frameworks exposing that configuration to users, networks or prompt injection inherited remote code execution, with 12+ CVEs across projects such as LangFlow, LiteLLM, Flowise and Windsurf. The Hacker News reports Anthropic characterized the protocol behavior as expected and did not change the reference design.

Check Point Research found that a cloned repository's Claude Code configuration could run hooks, start MCP servers before the user approved them, and redirect API traffic so the user's Anthropic API key was sent to an attacker (CVE-2025-59536, CVE-2026-21852). Anthropic fixed the issues between August and December 2025 by deferring execution and API calls until after the trust dialog.

VirusTotal analyzed more than 3,016 OpenClaw skill packages and reports hundreds with malicious behavior, including data exfiltration, backdoors, malware droppers such as Atomic Stealer, and persistent instruction files that manipulate the agent. One publisher accounted for 314 malicious skills; VirusTotal added native scanning of skill packages.

A package impersonating a Postmark email MCP server was published to npm and, after 15 clean versions, version 1.0.16 (2025-09-17) added code that blind-copied all emails sent through it to the publisher. Postmark stated it had never published an MCP server on npm; Koi Security found it, and the package was deleted after about 1,643 downloads.

Attackers exploited a GitHub Actions workflow injection to steal Nx's npm token and publish malicious versions whose install script scanned systems for secrets, attempted to use locally installed AI CLIs such as Claude and Gemini to assist, and uploaded results to public GitHub repositories. Nx reports the packages were live about four hours and has since moved to trusted publishing and mandatory 2FA approval.

Check Point Research found that Cursor bound MCP approval to a configuration's name rather than its contents, so a collaborator with repository write access could swap an approved harmless command for a malicious one that ran on each project open. Cursor 1.3, released 2025-07-29, prompts for approval on any MCP configuration change.

An actor used an improperly scoped GitHub token in AWS's build configuration to insert code into the Amazon Q Developer extension that instructed the agent to wipe local and cloud resources, and it shipped in version 1.84.0 on 2025-07-17. AWS says the code failed to execute due to a syntax error, no customer resources were affected, and it released 1.85.0 and assigned CVE-2025-8217.

JFrog reported CVE-2025-6514 (CVSS 9.6) in mcp-remote, a proxy used by MCP clients to reach remote servers, where a malicious server could supply a crafted OAuth authorization URL that led to command execution on the client machine. Versions 0.0.5 to 0.1.15 are affected and 0.1.16 fixes the issue.

The NSA AI Security Center, CISA, the FBI and international partners released a cybersecurity information sheet on securing data used to train and operate AI systems across the lifecycle. It recommends robust data protection, proactive risk management and stronger monitoring and threat detection, and is aimed at defense industrial base, national security system, federal and critical infrastructure operators.

Invariant Labs describes tool poisoning, in which instructions hidden in an MCP tool's description are visible to the model but not to the user, and shows proof-of-concept exfiltration of local files through an MCP client. It also describes rug pulls, where a server changes tool descriptions after approval, and shadowing, where one server's descriptions alter how the agent uses another server's tools. Recommended mitigations include showing full tool descriptions, pinning tool versions with checksums, and cross-server isolation.

Hou, Zhao, Wang and Wang survey MCP's architecture, industry adoption and server lifecycle. The first version (March 2025) split the lifecycle into creation, operation and update phases and discussed security risks in each. A revision in October 2025 expanded this to four phases with 16 activities and a threat taxonomy of four attacker types and 16 threat scenarios, with case studies and per-phase safeguards.