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.
CVE-2026-54335
LOWPre-NVD 3.73.7—
EchelonGraph scoreMEDIUM confidence
This low-severity CVE scores 3.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 69% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
3.7
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 3.7Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 3.7
- EG Score
- 3.7(medium)
- EG Risk
- 17(Track)EG Risk 17/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity37% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 31.5%
- KEV
- Not listed
Published
July 14, 2026
Last Modified
July 23, 2026
References (4)
- security-advisories@githubhttps://github.com/feathersjs/feathers/commit/28b3c03c63bdbff53115fdaa46c56980e7942acc
- security-advisories@githubhttps://github.com/feathersjs/feathers/pull/3690
- security-advisories@githubhttps://github.com/feathersjs/feathers/releases/tag/v5.0.45
- security-advisories@githubhttps://github.com/feathersjs/feathers/security/advisories/GHSA-28xv-ph75-77wh
Vendor Advisories for CVE-2026-54335(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
npm(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| @feathersjs/commons | — | 5.0.45 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 10× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 03:19 UTCEG score recompute
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:25 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 02:38 UTCEG score recompute
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-14 19:56 UTCEG score recompute
Related CVEs(same CWE)
Same CWE
10 shownCWE-1321
Frequently asked(5)
What is CVE-2026-54335?
CVE-2026-54335 is a low vulnerability published on July 14, 2026. 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…
When was CVE-2026-54335 disclosed?
CVE-2026-54335 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54335 actively exploited?
CVE-2026-54335 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 31.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-54335?
CVE-2026-54335 has a CVSS v3 base score of 3.7 (NVD).
How do I remediate CVE-2026-54335?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54335, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-54335
Is Your Infrastructure Affected by CVE-2026-54335?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.