CVE-2021-23558 is a critical-severity (CVSS 9.8) CWE-1321 vulnerability in bmoor. 1 public exploit reference exists, so weaponization risk is real. A fix is available for bmoor — see the affected versions and patch details below.
Prototype Pollution in bmoor
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-23558 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
bmoornpmDescription
The package bmoor before 0.10.1 are vulnerable to Prototype Pollution due to missing sanitization in set function. Note: This vulnerability derives from an incomplete fix in CVE-2020-7736
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | bmoor | all versions | 0.10.1npm install bmoor@0.10.1 |
Affected Products
bmoorbmoor_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for bmoor, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update bmoor to 0.10.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-23558 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2021-23558 in your dependencies?
Find it across npm, including transitive dependencies.