{"answers":{"affected":"1 open source package ship an affected version, including mcp-server-sequential-thinking.","exploited":"There is no known exploitation of MAL-2026-5484 in the wild and no public exploit code.","fix":"Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.","what":"MAL-2026-5484 is a malicious package in mcp-server-sequential-thinking, published on 9 Jun 2026."},"fix_prompt":"MAL-2026-5484 is a malicious package: mcp-server-sequential-thinking (npm). Every version was published to cause harm.\n\nTask:\n1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.\n2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.\n3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.\n4. If the package is not used anywhere, say so and change nothing.\n\nReference: https://insights.sbomify.com/MAL-2026-5484/ (Markdown: https://insights.sbomify.com/MAL-2026-5484/index.md)","id":"MAL-2026-5484","markdown":"https://insights.sbomify.com/MAL-2026-5484/index.md","name":"MAL-2026-5484","record":{"aliases":["GHSA-hrmj-jj6j-m2m2","GHSA-w69h-vf37-j4w6"],"analysis":null,"analysis_generated_by":null,"assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"Unscoped package impersonating the official @modelcontextprotocol/server-sequential-thinking MCP server. package.json declares postinstall: 'node index.js' and a bin entry mapping mcp-server-sequential-thinking to./index.js, so both `npm install` and `npx mcp-server-sequential-thinking` execute index.js automatically. index.js requires os/https/http and at lines 17-28 unconditionally POSTs a JSON payload containing os.hostname(), process.cwd(), the npm user-agent, Node version, and os.platform()/arch to https://npx-canary-log.vulnerable-live.workers.dev/log, a Cloudflare Workers endpoint controlled by the package author. The payload includes a `trigger` field that distinguishes postinstall vs bin-exec invocations, confirming the author intends to harvest both pathways. The package targets AI coding agents and developers who type the unscoped name expecting the official scoped MCP server. Although the README frames this as 'canary' research, installers do not consent, and host identifiers leave the machine to an attacker-controlled destination at install time.\n\nAny computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.","ecosystems":["npm"],"exploits":{"exploitdb":null,"first_seen":null,"github_poc":null,"max_poc_stars":null,"metasploit":null,"nuclei":null,"refs":[],"tier":null},"has_fix":false,"headline":"Malicious code in mcp-server-sequential-thinking (npm)","id":"MAL-2026-5484","indexable":true,"kev":null,"kind":"malicious","links":{"ecosystem":"npm","product":null,"products":[],"type":null,"year":"2026"},"n_packages":1,"n_references":null,"packages":[{"ecosystem":"npm","fixed":[],"introduced":["0"],"last_affected":[],"package":"mcp-server-sequential-thinking","purl":"pkg:npm/mcp-server-sequential-thinking","source":"MAL-2026-5484"}],"products":null,"published":"2026-06-09","related":[],"sources":[{"class":"attribution","licence":"Apache-2.0","name":"OpenSSF Malicious Packages","prefix":"MAL"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":null,"updated":null,"vendors":null},"summary":null,"url":"https://insights.sbomify.com/MAL-2026-5484/"}