fastify-cli vulnerable to remote code execution via ignored explicit Inspector bind address (CVE-2026-75021) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-75021

fastify-cli vulnerable to remote code execution via ignored explicit Inspector bind address

Answer in brief

CVE-2026-75021 records a Unknown severity vulnerability in fastify-cli vulnerable to remote code execution via ignored explicit Inspector bind address. The current sources do not mark it as known exploited. The current feed maps fastify-cli/fastify-cli (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 8, 2026Updated Sep 8, 2026Source checked Sep 8, 2026First seen by HOL Sep 8, 2026Material review Sep 8, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps fastify-cli/fastify-cli (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
fastify-cli/fastify-cligeneric	>=1.5.0 <8.0.1	8.0.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for fastify-cli/fastify-cli.
Review the reported fix. Update fastify-cli/fastify-cli to 8.0.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 8, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 8, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 8, 2026

Sources and claim methodology

Upstream source description

fastify-cli starts the Node.js Inspector when a debug flag is used, but it ignores the explicit bind address the user supplies and binds the Inspector to a broadly reachable address instead of the intended loopback. As a result the debugging interface can be exposed beyond the local machine, and because the Inspector protocol allows arbitrary code evaluation, a remote party that reaches it can achieve remote code execution on the developer's machine. This affects fastify-cli from 1.5.0 up to 8.0.1. Users should upgrade to fastify-cli 8.0.1, which honors the configured Inspector bind address.

Quoted source text, attributed separately from HOL analysis.