What’s Vulnerable › Vulnerabilities

CVE-2021-23433: Prototype Pollution

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-11-19 · updated 2026-06-17
• Weakness: CWE-1321

Description

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 products

• algoliasearch-helper: before 3.6.2 — fixed in 3.6.2

How to fix

Upgrade to a fixed version: algoliasearch-helper 3.6.2. Check the vendor advisory for mitigations.

References

• https://github.com/algolia/algoliasearch-helper-js/blob/3.5.5/src/SearchParameters/index.js%23L291
• https://github.com/algolia/algoliasearch-helper-js/commit/4ff542b70b92a6b81cce8b9255700b0bc0817edd
• https://snyk.io/vuln/SNYK-JS-ALGOLIASEARCHHELPER-1570421
• https://github.com/algolia/algoliasearch-helper-js/blob/3.5.5/src/SearchParameters/index.js%23L291
• https://github.com/algolia/algoliasearch-helper-js/commit/4ff542b70b92a6b81cce8b9255700b0bc0817edd
• https://snyk.io/vuln/SNYK-JS-ALGOLIASEARCHHELPER-1570421

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