Remote code execution via ignored Inspector bind address
Published Sep 8, 2026 · Updated Sep 8, 2026
Remote code execution in Fastify CLI 1.5.0 through 8.0.0 allows remote attackers to execute code through an exposed Node.js Inspector. The debug startup path discards the explicit Inspector bind address and starts Node.js with a broadly reachable listener instead of the requested loopback address. Exploitation requires debug mode and network access to that listener; successful access permits arbitrary JavaScript evaluation in the developer process.
Summary
What happened
Remote code execution in Fastify CLI 1.5.0 through 8.0.0 allows remote attackers to execute code through an exposed Node.js Inspector. The debug startup path discards the explicit Inspector bind address and starts Node.js with a broadly reachable listener instead of the requested loopback address. Exploitation requires debug mode and network access to that listener; successful access permits arbitrary JavaScript evaluation in the developer process.
The record
- CVE
- CVE-2026-75021
- Published
- Sep 8, 2026
- Updated
- Sep 8, 2026
- Vendor
- Fastify
- Product
- Fastify CLI
- Classifications
- T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 8, 2026CVE publishedPublication date reported by the CVE source.
- Sep 8, 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=1.5.0 <8.0.1
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
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Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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