PatchTheCVECVE-2020-35149: lib/utils.js in mquery before 3.2.3 allows a pollution attack because a special property (e.g., __proto__) can
CVE-2020-35149 is a medium-severity flaw (CVSS 5.3) affecting mquery. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
lib/utils.js in mquery before 3.2.3 allows a pollution attack because a special property (e.g., __proto__) can be copied during a merge or clone operation.
Why this priority
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.3 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.0% (top 36%) |
| CISA exploited list | No |
| Published | 2020-12-11 |
| 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-2020-35149?
mquery: upgrade to 3.2.3. Exact commands for each OS are on this page.
Is CVE-2020-35149 being exploited?
CVE-2020-35149 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-2020-35149 affect?
CVE-2020-35149 affects mquery. Severity is medium (CVSS 5.3). lib/utils.js in mquery before 3.2.3 allows a pollution attack because a special property (e.g., __proto__) can be copied during a merge or clone operation.
How urgent is CVE-2020-35149?
Priority 40/100. Remotely exploitable, no login, no user action