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📦 npm
Not in CISA KEV
HIGH severity

CVE-2021-23430 — startserver

HIGH

CVE-2021-23430 is a high-severity (CVSS 7.5) Path Traversal vulnerability in startserver. 1 public exploit reference exists, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.

Directory Traversal in startserver

Published
Updated
Affected
1 pkg
Patched
See advisory
Exploits
1 known
Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
1.8%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs78th percentile — riskier than 78% of all scored CVEsHighest risk
0.00%0.76%1.52%2.28%0.4%1.8%Apr 26Aug 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-23430 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

0other npm packages depend on this — each one inherits the vulnerability until it's patched upstream
startservernpm
262downloads / week

Description

All versions of package startserver are vulnerable to Directory Traversal due to missing sanitization.

Affected Packages

1 total
EcosystemPackageVulnerable rangeFix
📦npmstartserverall versionsNo fix

Affected Products

1 product · 1 configurations
Application
startserverstartserver_project
all
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

All versions of package startserver are vulnerable to Directory Traversa…

snyk.ioNVDAug 2021

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for startserver, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Remediation status

    No patched version of startserver has shipped for CVE-2021-23430 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

  3. Mitigate without a patch

    Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Frequently Asked Questions

All versions of package startserver are vulnerable to Directory Traversal due to missing sanitization.
O3 Security · Impact-Aware SCA

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