Vulnerability Description
Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. In 5.0.44 and earlier, the _.merge(target, source) utility exported by @feathersjs/commons recursively merges source into target by iterating Object.keys(source). When source was produced by JSON.parse and contains a __proto__, constructor, or prototype key, that key is returned as an own-enumerable property; the recursive merge then resolves target['__proto__'] to Object.prototype and writes attacker-supplied properties onto it, polluting the prototype for all plain objects in the process for the lifetime of the Node process. This issue is fixed in version 5.0.45.
CVSS Score
LOW
Related Weaknesses (CWE)
References
- https://github.com/feathersjs/feathers/commit/28b3c03c63bdbff53115fdaa46c56980e7
- https://github.com/feathersjs/feathers/pull/3690
- https://github.com/feathersjs/feathers/releases/tag/v5.0.45
- https://github.com/feathersjs/feathers/security/advisories/GHSA-28xv-ph75-77wh
FAQ
What is CVE-2026-54335?
CVE-2026-54335 is a vulnerability with a CVSS score of 3.7 (LOW). Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. In 5.0.44 and earlier, the _.merge(target, source) utility exported by @feathersjs/commons rec...
How severe is CVE-2026-54335?
CVE-2026-54335 has been rated LOW with a CVSS base score of 3.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-54335?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.