Miniflare vulnerable to Server-Side Request Forgery (SSRF)GHSA-fwvg-2739-22v7
HIGHFix: cloudflare/workers-sdk#4532GHSA-fwvg-2739-22v7 is a high-severity (CVSS 7.5) Server-Side Request Forgery (SSRF) vulnerability in miniflare. A fix is available for miniflare — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-fwvg-2739-22v7.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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.
miniflarenpmDescription
Impact
Sending specially crafted HTTP requests to Miniflare's server could result in arbitrary HTTP and WebSocket requests being sent from the server. If Miniflare was configured to listen on external network interfaces (as was the default in wrangler until 3.19.0), an attacker on the local network could access other local servers.
Patches
The issue was fixed in [email protected].
Workarounds
Ensure Miniflare is configured to listen on just local interfaces. This is the default behaviour, but can also be configured with the host: "127.0.0.1" option.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | miniflare | ≥ 3.20230821.0&&< 3.20231030.2 | 3.20231030.2npm install miniflare@3.20231030.2 |
Affected Products
miniflarecloudflareDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for miniflare, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update miniflare to 3.20231030.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fwvg-2739-22v7 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.
Frequently Asked Questions
Is GHSA-fwvg-2739-22v7 in your dependencies?
Find it across npm, including transitive dependencies.