CVE-2026-54335 json
Feathersjs: Prototype pollution in @feathersjs/commons _.merge via JSON-parsed __proto__
published 2026-07-14 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-45337 , GHSA-28xv-ph75-77wh
- cvss
- 3.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 33%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm @feathersjs/commons 5.0.45
- feathersjs feathers 5.0.45
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 3 mo ago
Exploit prediction
0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N |
| GitHub | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | @feathersjs/commons | <5.0.45 |
5.0.45 |
Affected products
- feathersjs feathers
Classification
- Weakness
-
- CWE-1321 Improperly Controlled Modification of Object Prototype Attributes
References
-
github.com
/feathersjs/feathers/pull/3690
web
-
github.com
/feathersjs/feathers/commit/28b3c03c63bdbff53115fdaa46c56980e7942acc
web
-
github.com
/feathersjs/feathers/security/advisories/GHSA-28xv-ph75-77wh
web
-
github.com
/feathersjs/feathers/releases/tag/v5.0.45
web
-
github.com
/feathersjs/feathers
package
Sources
- CVE List CVE-2026-54335
- GitHub Advisory GHSA-28xv-ph75-77wh
- NVD CVE-2026-54335
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.