{"answers":{"affected":"1 open source package ship an affected version, including react-cleaner.","exploited":"There is no known exploitation of MAL-2026-4791 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-2026-4791 is a malicious package in react-cleaner, published on 26 May 2026."},"fix_prompt":"MAL-2026-4791 is a malicious package: react-cleaner (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-2026-4791/ (Markdown: https://insights.sbomify.com/MAL-2026-4791/index.md)","id":"MAL-2026-4791","markdown":"https://insights.sbomify.com/MAL-2026-4791/index.md","name":"MAL-2026-4791","record":{"aliases":[],"analysis":null,"analysis_generated_by":null,"assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"react-cleaner@1.0.4 is a pino-logger impersonator (package main is pino.js, homepage https://getpino.io, module layout mirrors pino's lib/ tree) that, on require, executes attacker-controlled remote code with the installer's environment in scope. lib/writer.js calls axios.get('https://www.jsonkeeper.com/b/MYUKZ') and passes the response body directly to eval(). jsonkeeper.com is a mutable paste-style host, so the author can rotate the executed payload at any time without republishing. Before the fetch, writer.js assembles a data object containing the entirety of process.env, os.hostname(), os.userInfo().username, os.platform(), and the host's non-internal MAC addresses; this object is in scope when the remote payload runs, giving the attacker direct access to AWS_*, GITHUB_TOKEN, NPM_TOKEN, and any other secrets present in the installer's environment. A second remote-code channel is hex-obfuscated alongside the plaintext one: a hl array decodes to 'axios','get','https://www.jsonkeeper.com/b/HY6M6','then', confirming deliberate concealment of a backup eval source. The combination — pino impersonation as cover, require-time fetch-and-eval from a mutable anonymous host, bulk env scrape staged in eval scope, hex-obfuscated secondary URL — is an unambiguous credential-harvesting RCE.","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 react-cleaner (npm)","id":"MAL-2026-4791","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":[],"last_affected":[],"package":"react-cleaner","purl":"pkg:npm/react-cleaner","source":"MAL-2026-4791"}],"products":null,"published":"2026-05-26","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-2026-4791/"}