PatchTheCVECVE-2020-28499: All versions of package merge are vulnerable to Prototype Pollution via _recursiveMerge .
CVE-2020-28499 is a high-severity flaw (CVSS 7.3) affecting merge. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
All versions of package merge are vulnerable to Prototype Pollution via _recursiveMerge .
Why this priority
- High severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.3 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.4% (top 27%) |
| CISA exploited list | No |
| Published | 2021-02-18 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2020-28499?
merge: upgrade to 2.1.1. Exact commands for each OS are on this page.
Is CVE-2020-28499 being exploited?
CVE-2020-28499 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2020-28499 affect?
CVE-2020-28499 affects merge. Severity is high (CVSS 7.3). All versions of package merge are vulnerable to Prototype Pollution via _recursiveMerge .
How urgent is CVE-2020-28499?
Priority 49/100. High severity; Remotely exploitable, no login, no user action
Related CVEs
- CVE-2021-3645 CRITICAL 9.8 UPGRADE merge is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution
- CVE-2021-23397 MEDIUM 5.6 MITIGATE All versions of package @ianwalter/merge are vulnerable to Prototype Pollution via the main (merge) function