Prototype pollution via unchecked constructor merge
Published Sep 27, 2025 · Updated Sep 27, 2025
Prototype pollution in Algolia algoliasearch-helper 2.0.0-rc1 through 3.11.1 allows remote attackers to alter Object.prototype. The _merge function in merge.js recursively copies attacker-controlled constructor.prototype properties because it filters proto but not constructor. Exploitation requires an application to accept user-controlled searchParameters and catch the resulting error; InstantSearch's default configuration does not expose that input.
Summary
What happened
Prototype pollution in Algolia algoliasearch-helper 2.0.0-rc1 through 3.11.1 allows remote attackers to alter Object.prototype. The _merge function in merge.js recursively copies attacker-controlled constructor.prototype properties because it filters proto but not constructor. Exploitation requires an application to accept user-controlled searchParameters and catch the resulting error; InstantSearch's default configuration does not expose that input.
The record
- CVE
- CVE-2025-3193
- Published
- Sep 27, 2025
- Updated
- Sep 27, 2025
- Vendor
- Algolia
- Product
- algoliasearch-helper
- Classifications
- CWE-1321
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 27, 2025CVE publishedPublication date reported by the CVE source.
- Sep 27, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.0.0-rc1 <3.11.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Snyk constructor.prototype proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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