CVE-2025-57755 — @musistudio/claude-code-r…
NONECVE-2025-57755 is a none-severity (CVSS 0) Information Exposure vulnerability in @musistudio/claude-code-router. A fix is available for @musistudio/claude-code-router — see the affected versions and patch details below.
@musistudio/claude-code-router has improper CORS configuration
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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 CVE-2025-57755.
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
CVE-2025-57755 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 378,156 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
@musistudio/claude-code-routerReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
claude-code-router is a powerful tool to route Claude Code requests to different models and customize any request. Due to improper Cross-Origin Resource Sharing (CORS) configuration, there is a risk that user API Keys or equivalent credentials may be exposed to untrusted domains. Attackers could exploit this misconfiguration to steal credentials, abuse accounts, exhaust quotas, or access sensitive data. The issue has been patched in v1.0.34.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @musistudio/claude-code-router | all versions | 1.0.34npm install @musistudio/claude-code-router@1.0.34 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @musistudio/claude-code-router, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @musistudio/claude-code-router to 1.0.34 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-57755 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 CVE-2025-57755 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-57755. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-57755 in your dependencies?
O3 Security finds CVE-2025-57755 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.