PatchTheCVECVE-2021-23700: All versions of package merge-deep2 are vulnerable to Prototype Pollution via the mergeDeep() function.
CVE-2021-23700 is a medium-severity flaw (CVSS 6.5) affecting merge-deep2. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
All versions of package merge-deep2 are vulnerable to Prototype Pollution via the mergeDeep() function.
Why this priority
- Public exploit reference
- Remotely exploitable, no login, no user action
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 6.5 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.2% (top 32%) |
| CISA exploited list | No |
| Weakness | CWE-1321 |
| Published | 2021-12-10 |
| 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-2021-23700?
merge-deep2: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2021-23700 being exploited?
CVE-2021-23700 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-2021-23700 affect?
CVE-2021-23700 affects merge-deep2. Severity is medium (CVSS 6.5). All versions of package merge-deep2 are vulnerable to Prototype Pollution via the mergeDeep() function.
How urgent is CVE-2021-23700?
Priority 50/100. Public exploit reference; Remotely exploitable, no login, no user action