Arbitrary code execution via malicious postinstall hook
Published Aug 10, 2026 · Updated Aug 10, 2026
Malicious postinstall code in react18-use commit 7b79148d1495a2505f9277da295a98cf176f4496 allows remote attackers to execute code during npm install. The src/install.js postinstall hook disables TLS verification, fetches JavaScript from an attacker-controlled HTTPS endpoint, and evaluates it with require available. Execution requires npm install from the affected checkout on a developer workstation; CI and cloud or serverless environments are skipped, and the Node process's user permissions bound the compromise.
Summary
What happened
Malicious postinstall code in react18-use commit 7b79148d1495a2505f9277da295a98cf176f4496 allows remote attackers to execute code during npm install. The src/install.js postinstall hook disables TLS verification, fetches JavaScript from an attacker-controlled HTTPS endpoint, and evaluates it with require available. Execution requires npm install from the affected checkout on a developer workstation; CI and cloud or serverless environments are skipped, and the Node process's user permissions bound the compromise.
The record
- CVE
- CVE-2026-48161
- Published
- Aug 10, 2026
- Updated
- Aug 10, 2026
- Vendor
- Daishi Kato
- Product
- react18-use
- Classifications
- T1059.007, T1195.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 19, 2026Exploitation reportedMalicious react18-use repository compromise
- Aug 10, 2026CVE publishedPublication date reported by the CVE source.
- Aug 10, 2026Record 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=>= 7b79148d1495a2505f9277da295a98cf176f4496, <= 7b79148d1495a2505f9277da295a98cf176f4496
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
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
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- Malicious react18-use repository compromisereported exploitation
Technologies
Your stack
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Your stack
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