CVE-2026-54335: CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in feathersjs feathers
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.
AI Analysis
Technical Summary
Feathersjs versions 5.0.44 and earlier contain a prototype pollution vulnerability in the _.merge(target, source) function exported by @feathersjs/commons. When source objects parsed from JSON include keys such as __proto__, constructor, or prototype, these keys are treated as own-enumerable properties and merged recursively into the target object. This results in attacker-controlled properties being written to Object.prototype, polluting the prototype chain for all plain objects in the Node.js process. This vulnerability is addressed in Feathersjs version 5.0.45.
Potential Impact
The vulnerability allows an attacker to modify the prototype of all plain objects in the Node.js process by injecting properties via specially crafted JSON input. This can lead to unexpected behavior or logic errors in applications relying on Feathersjs, potentially causing integrity issues. The CVSS score is 3.7 (low severity), indicating limited impact with no direct confidentiality or availability effects.
Mitigation Recommendations
Upgrade Feathersjs to version 5.0.45 or later, where this prototype pollution vulnerability is fixed. No other official remediation or temporary fixes are indicated. Patch status is confirmed by the vendor's versioning information.
CVE-2026-54335: CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in feathersjs feathers
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 v3.1
Score 3.7low
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Feathersjs versions 5.0.44 and earlier contain a prototype pollution vulnerability in the _.merge(target, source) function exported by @feathersjs/commons. When source objects parsed from JSON include keys such as __proto__, constructor, or prototype, these keys are treated as own-enumerable properties and merged recursively into the target object. This results in attacker-controlled properties being written to Object.prototype, polluting the prototype chain for all plain objects in the Node.js process. This vulnerability is addressed in Feathersjs version 5.0.45.
Potential Impact
The vulnerability allows an attacker to modify the prototype of all plain objects in the Node.js process by injecting properties via specially crafted JSON input. This can lead to unexpected behavior or logic errors in applications relying on Feathersjs, potentially causing integrity issues. The CVSS score is 3.7 (low severity), indicating limited impact with no direct confidentiality or availability effects.
Mitigation Recommendations
Upgrade Feathersjs to version 5.0.45 or later, where this prototype pollution vulnerability is fixed. No other official remediation or temporary fixes are indicated. Patch status is confirmed by the vendor's versioning information.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-12T19:23:22.316Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a5b401b34329bf928c718f3
Added to database: 07/18/2026, 08:58:03 UTC
Last enriched: 07/25/2026, 22:47:23 UTC
Last updated: 08/31/2026, 22:52:12 UTC
Views: 81
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