modern-localization

Details

**Severity:** Critical

**Affected versions:** `= 1.1.1`

## Source: amazon-inspector (4be23667d11e7ef3357641973b9188175c2068bd2b580a5628773bcdf03533a5)
On server-side require of modern-localization, the package's main entry runs a top-level async IIFE (syncLanguageSystem) that performs an HTTP GET against a hardcoded jsonbin.io endpoint (https://api.jsonbin.io/v3/b/6a764665da38895dfec7cd5d and https://api.jsonbin.io/v3/b/6a718a58da38895dfeb6e2ed) and executes the returned string as JavaScript with full Node privileges. utils.js passes the fetched record.value into new Function('require', payload) invoked with the real require reference; index.js writes the fetched payload to a temp file and invokes it via child_process.fork. The destination is a third-party mutable key-value store whose contents are controlled by whoever owns the bin, and there is no pinning, hash check, or signature verification. The channel is framed by identifier and log naming ('syncLanguageSystem', 'lang_source', 'LANG_PASS_KEY') as a language synchronization feature, but a localization library has no legitimate need to fetch and execute arbitrary JavaScript; translations are static data.

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Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/1ea2762d5fb415aef003a244d5aa83c5fc48cc6e/osv/malicious/npm/modern-localization/MAL-2026-13633.json))

**References:**
- https://github.com/ossf/malicious-packages/blob/1ea2762d5fb415aef003a244d5aa83c5fc48cc6e/osv/malicious/npm/modern-localization/MAL-2026-13633.json
- https://www.npmjs.com/package/modern-localization/v/1.1.1
- https://www.npmjs.com/package/modern-localization/v/1.2.1
- https://github.com/advisories/GHSA-qf2g-q6rj-77q5

Compromised versions (1)

• = 1.1.1

Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.