Skip to content

← Actionable
Critical, CVSS 9.8amended

Prototype Pollution in merge-recursive

CVE-2018-3751GHSA-cvxm-f295-x957

What to do

Vendor response not established. Follow the primary source's mitigation guidance and check back for a fix.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Affected packages

  • npm merge-recursive

    Affected
    <= 0.0.3
    Fixed in
    no fixed version recorded

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS
9.8 · CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
  • CVE-2018-3751: 1.43% estimated exploitation activity in the next 30 days; percentile 73.02 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

All versions of merge-recursive are vulnerable to Prototype Pollution. When malicious user input is merged with another object it allows the attacker to modify the prototype of Object via proto causing the addition or modification of an existing property. Proof of concept: Recommendation There is currently no fix available.

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 2 · amended ·

    Amended from ghsa record GHSA-cvxm-f295-x957

  2. Revision 1 · created ·

    Published from osv record GHSA-cvxm-f295-x957

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2018-3751

Advisory: Prototype Pollution in merge-recursive
IDs: CVE-2018-3751, GHSA-cvxm-f295-x957
Record: https://patchnext.com/advisories/cve-2018-3751 (revision 2, source checked 26 Oct 2026, 12:26 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm merge-recursive: affected <= 0.0.3

## Suggested inspection (read-only)
- `npm ls merge-recursive --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on merge-recursive.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-cvxm-f295-x957 (OSV record GHSA-cvxm-f295-x957 lists affected ranges: npm merge-recursive >=0 <=0.0.3)
- Verified: https://github.com/advisories/GHSA-cvxm-f295-x957 (GitHub-reviewed advisory GHSA-cvxm-f295-x957 lists affected ranges: npm merge-recursive >=0 <=0.0.3)

Commands are suggestions: review each one before running it.

Loading voting…