CVE-2021-23433 is a critical-severity (CVSS 9.8) CWE-1321 vulnerability in algoliasearch-helper. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for algoliasearch-helper — see the affected versions and patch details below.
Prototype Pollution in algoliasearch-helper
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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.
algoliasearch-helpernpmDescription
The package algoliasearch-helper before 3.6.2 are vulnerable to Prototype Pollution due to use of the merge function in src/SearchParameters/index.jsSearchParameters._parseNumbers without any protection against prototype properties. Note that this vulnerability is only exploitable if the implementation allows users to define arbitrary search patterns.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | algoliasearch-helper | all versions | 3.6.2npm install algoliasearch-helper@3.6.2 |
Affected Products
algoliasearch-helperalgoliaResearch 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 algoliasearch-helper, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update algoliasearch-helper to 3.6.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-23433 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-2021-23433 in your dependencies?
Find it across npm, including transitive dependencies.