Prototype Pollution in merge

CRITICAL 9.8CVE-2020-28499 · GHSA-7wpw-2hjm-89gp · Published 18/02/2021 · updated 17/06/2026

In short

CVE-2020-28499 is a CRITICAL (CVSS 9.8) vulnerability affecting merge (merge project), merge.
Chance of exploitation in the next 30 days (EPSS): 1.4%, higher than 73.4% of all vulnerabilities.
Fix: update to 2.1.1 or later.

Package	Affected versions	Patched versions
merge merge_project	`< 2.1.1`	`2.1.1`
merge npm	`< 2.1.1`	`2.1.1`

All versions of package merge <2.1.1 are vulnerable to Prototype Pollution via _recursiveMerge .

NVD description

All versions of package merge are vulnerable to Prototype Pollution via _recursiveMerge .

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