Prototype pollution in Merge-deep
Published Jun 2, 2021 · Updated Oct 23, 2026 · Also known as GHSA-r6rj-9ch6-g264
Original summary
Normalized public record · Updated Oct 23, 2026
Prototype pollution in Merge-deep
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
The merge-deep library before 3.0.3 for Node.js can be tricked into overwriting properties of Object.prototype or adding new properties to it. These properties are then inherited by every object in the program, thus facilitating prototype-pollution attacks against applications using this library.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- MEDIUM
- Confidence
- 20%
- Aliases
- GHSA-r6rj-9ch6-g264
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
Record history
Published Jun 2, 2021 · Last refreshed Oct 23, 2026