TL;DR
Researchers have documented multiple Claude Code security issues involving local configuration files, MCP integrations and repository hooks. Check Point flaws were patched, while a Mitiga-described token-theft path is reported as outside Anthropic’s patch scope.
Security researchers have documented Claude Code security risks that can turn local configuration files, MCP integrations and repository hooks into paths for token theft or code execution, a development that matters because coding agents often sit near source code, internal services and SaaS credentials.
Confirmed: Check Point Research reported CVE-2025-59536, described in the source material as remote code execution through repository hooks, and CVE-2026-21852, described as API-key exfiltration. The same source material says Anthropic patched those reported issues after disclosure.
Claimed by researchers: Mitiga Labs described a token-theft chain in which a malicious npm package could alter Claude Code’s local configuration and redirect authenticated MCP traffic. The reported risk centers on long-lived OAuth tokens connected to services such as GitHub, Jira and Confluence.
SecurityWeek and all-about-security were cited in the source material as reporting that a packaging error exposed unencrypted Claude Code source, which could then be used in fake GitHub repositories and malware lures. Details about the scale of that activity remain limited in the provided material.
Your Coding Agent Is an Attack Surface
● SecurityThree disclosed flaws turned Claude Code’s local config and MCP integrations into silent paths for token theft and code execution. Some fixes are yours to make — and the lesson applies to every agentic dev tool, not one.
The config files most teams treat as passive metadata are, in practice, active execution paths.
~/.claude.json, reroutes MCP traffic, and intercepts long-lived OAuth tokens for GitHub, Jira, Confluence.How the unpatched Mitiga path works — at the level its researchers published. (Defensive overview, no exploit detail.)
~/.claude.json.For teams running Claude Code — or any coding agent — in production.
~/.claude.json/permissions; disconnect what you don’t use.Anthropic patched the Check Point CVEs fast — responsible disclosure worked. The npm post-install hook is an industry-wide supply-chain risk class, not Anthropic’s invention.
Anthropic calls the Mitiga chain “out of scope.” But consenting to install a package isn’t consenting to having your SaaS credentials intercepted — and plaintext tokens in the router file turn a generic risk into a specific one.
Independent commentary, produced with AI assistance under human editorial oversight; the views are the author’s own and may change. This is security analysis and opinion, not professional security, legal, or financial advice; verify specifics against vendor advisories and the primary research before acting. It describes publicly disclosed vulnerabilities at the level reported by their researchers and is for defensive purposes only — no exploit code or attack instructions. Sources: Computerwoche (Anjali Gopinadhan Nair), Mitiga Labs, Check Point Research, SecurityWeek, all-about-security, and Anthropic’s documentation, read as of June 2026. References to companies, researchers, and CVEs are factual and analytical and imply no affiliation or endorsement.
Agent Tokens Reach Farther
The disclosures point to a broader issue for teams using coding agents in production workflows: an agent credential can reach beyond a browser session. Depending on how a team configures MCP connectors, a compromised agent setup may touch source repositories, ticketing systems, documentation platforms, cloud tools or internal APIs.
The risk is not limited to Claude Code. The source material frames npm install hooks, plaintext local configuration and broad connector permissions as supply-chain and workstation risks that can affect agentic development tools across the market.
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Three Disclosures Converged
The June 2026 Thorsten Meyer AI dispatch and a Computerwoche commentary by cybersecurity engineer Anjali Gopinadhan Nair presented the disclosures as part of one pattern: files and hooks that developers often treat as passive can become execution and routing paths.
The MCP model gives coding agents access to external tools and services. That access is useful for development work, but it also means local config changes, connector scopes and repo-level automation need the same attention teams give production secrets and CI systems.
“The config files most teams treat as passive metadata are, in practice, active execution paths.”
— Thorsten Meyer AI dispatch
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Patch Scope Leaves Gaps
It is not yet clear from the supplied material whether the Mitiga-described token-theft path has been exploited against real developer environments. The source material also does not provide incident counts, affected customer numbers or a final vendor plan for the disputed chain.
The reported source-code exposure and fake-repository lures are described as active risks, but the scale, targets and confirmed infections are still developing.
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Teams Audit Agent Access
Teams using Claude Code or similar coding agents are expected to update patched versions, review local agent configuration, watch for unexpected MCP endpoints or proxy changes, and restrict connector scopes. The defensive guidance in the source material also calls for reviewing npm post-install behavior, cleaning affected hosts before token rotation and disconnecting integrations that are no longer needed.
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Key Questions
What is the actual news here?
Researchers have tied multiple Claude Code disclosures to risks in local config, MCP integrations and repository hooks, including patched CVEs and one reported token-theft chain that remains disputed.
Are the Claude Code CVEs fixed?
According to the supplied source material, Anthropic patched the Check Point Research issues identified as CVE-2025-59536 and CVE-2026-21852.
Does this affect only Claude Code?
No. The article frames Claude Code as the visible case, while npm hooks, agent configs and broad connector tokens are risks for agentic developer tools more broadly.
Has token theft been confirmed in the wild?
The supplied material describes Mitiga’s reported attack chain but does not confirm real-world victim counts or documented theft from production environments.
Source: Thorsten Meyer AI
