GHSA-cfph-4qqh-w828 is a medium-severity (CVSS 6.9) Improper Authentication vulnerability in wrangler. A fix is available for wrangler — see the affected versions and patch details below.
Arbitrary remote file read in Wrangler dev server
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-cfph-4qqh-w828 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
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.
wranglernpmDescription
Impact
Sending specially crafted HTTP requests and inspector messages to Wrangler's dev server could result in any file on the user's computer being accessible over the local network. An attacker that could trick any user on the local network into opening a malicious website could also read any file.
Patches
This issue was fixed in [email protected]. Wrangler will now only serve files that are part of your bundle, or referenced by your bundle's source maps.
Workarounds
Configure Wrangler to listen on local interfaces instead with wrangler dev --ip 127.0.0.1. This is the default as of [email protected], and removes the local network as an attack vector, but does not prevent an attack from visiting a malicious website.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | wrangler | ≥ 3.9.0&&< 3.19.0 | 3.19.0npm install wrangler@3.19.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wrangler, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update wrangler to 3.19.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cfph-4qqh-w828 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-cfph-4qqh-w828 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-cfph-4qqh-w828. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-cfph-4qqh-w828 in your dependencies?
O3 Security finds GHSA-cfph-4qqh-w828 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.