CVE-2020-28276 — deep-set
CRITICALCVE-2020-28276 is a critical-severity (CVSS 9.8) remote code execution vulnerability in deep-set. 2 public exploit references exist, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.
Prototype pollution vulnerability in 'deep-set'
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2020-28276 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
deep-setnpmDescription
The NPM module 'deep-set' can be abused by Prototype Pollution vulnerability since the function deepSet() does not check for the type of object before assigning value to the property. Due to this flaw an attacker could create a non-existent property or able to manipulate the property which leads to Denial of Service or potentially Remote code execution.
PoC
var deepSet = require('deep-set')
var obj = {'1':'2'}
console.log(obj.isAdmin);
deepSet(obj, '__proto__.isAdmin', 'true')
console.log(obj.isAdmin);
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | deep-set | ≥ 1.0.0 | No fix |
Research 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 deep-set, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of deep-set has shipped for CVE-2020-28276 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2020-28276 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2020-28276. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2020-28276 in your dependencies?
O3 Security finds CVE-2020-28276 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.