CVE-2025-59331

is-arrayish@0.3.3 contains malware after npm account takeover

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Published Sep 15, 2025 CVSS 4.0 · 8.8 High EPSS < 1% KEV · Not listed
Description
is-arrayish checks if an object can be used like an Array. On 8 September 2025, an npm publishing account for is-arrayish was taken over after a phishing attack. Version 0.3.3 was published, functionally identical to the previous patch version, but with a malware payload added attempting to redirect cryptocurrency transactions to the attacker's own addresses from within browser environments. Local environments, server environments, command line applications, etc. are not affected. If the package was used in a browser context (e.g. a direct <script> inclusion, or via a bundling tool such as Babel, Rollup, Vite, Next.js, etc.) there is a chance the malware still exists and such bundles will need to be rebuilt. The malware seemingly only targets cryptocurrency transactions and wallets such as MetaMask. See references below for more information on the payload. npm removed the offending package from the registry over the course of the day on 8 September, preventing further downloads from npm proper. On 13 September, the package owner published new patch versions to help cache-bust those using private registries who might still have the compromised version cached. Users should update to the latest patch version, completely remove their node_modules directory, clean their package manager's global cache, and rebuild any browser bundles from scratch. Those operating private registries or registry mirrors should purge the offending versions from any caches. This issue is resolved in 0.3.4.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2025-29241 is-arrayish checks if an object can be used like an Array. On 8 September 2025, an npm publishing account for is-arrayish was taken over after a phishing attack. Version 0.3.3 was published, functionally identical to the previous patch version, but with a malware payload added attempting to redirect cryptocurrency transactions to the attacker's own addresses from within browser environments. Local environments, server environments, command line applications, etc. are not affected. If the package was used in a browser context (e.g. a direct <script> inclusion, or via a bundling tool such as Babel, Rollup, Vite, Next.js, etc.) there is a chance the malware still exists and such bundles will need to be rebuilt. The malware seemingly only targets cryptocurrency transactions and wallets such as MetaMask. See references below for more information on the payload. npm removed the offending package from the registry over the course of the day on 8 September, preventing further downloads from npm proper. On 13 September, the package owner published new patch versions to help cache-bust those using private registries who might still have the compromised version cached. Users should update to the latest patch version, completely remove their node_modules directory, clean their package manager's global cache, and rebuild any browser bundles from scratch. Those operating private registries or registry mirrors should purge the offending versions from any caches. This issue is resolved in 0.3.4.
Github GHSA Github GHSA GHSA-frh7-2f84-v9mw is-arrayish@0.3.3 contains malware after npm account takeover
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}
Type Values Removed Values Added
Description is-arrayish checks if an object can be used like an Array. On 8 September 2025, an npm publishing account for is-arrayish was taken over after a phishing attack. Version 0.3.3 was published, functionally identical to the previous patch version, but with a malware payload added attempting to redirect cryptocurrency transactions to the attacker's own addresses from within browser environments. Local environments, server environments, command line applications, etc. are not affected. If the package was used in a browser context (e.g. a direct <script> inclusion, or via a bundling tool such as Babel, Rollup, Vite, Next.js, etc.) there is a chance the malware still exists and such bundles will need to be rebuilt. The malware seemingly only targets cryptocurrency transactions and wallets such as MetaMask. See references below for more information on the payload. npm removed the offending package from the registry over the course of the day on 8 September, preventing further downloads from npm proper. On 13 September, the package owner published new patch versions to help cache-bust those using private registries who might still have the compromised version cached. Users should update to the latest patch version, completely remove their node_modules directory, clean their package manager's global cache, and rebuild any browser bundles from scratch. Those operating private registries or registry mirrors should purge the offending versions from any caches. This issue is resolved in 0.3.4.
Title is-arrayish@0.3.3 contains malware after npm account takeover
Weaknesses CWE-506
References
Metrics cvssV4_0

{'score': 8.8, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:A/U:Red'}

Subscriptions

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Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 15, 2025, 7:39 PM
Reserved
Sep 12, 2025, 12:36 PM

View source JSON

Updated
Sep 15, 2025, 7:39 PM

JSON

Status
Deferred
Published
Sep 15, 2025, 8:15 PM
Modified
Jun 17, 2026, 9:45 AM

View source JSON

Severity
Important
Public date
Sep 15, 2025, 7:21 PM

View source Bugzilla JSON

No data.