CVE-2026-75601: Static Web Server: Authentication bypass on /metrics endpoint when --basic-auth is enabled
Static Web Server (SWS) is a production-ready web server suitable for static web files or assets. Through 2.43.0, instances with both basic-auth and metrics features enabled process the /metrics endpoint before the basic-auth check in src/handler.rs, allowing an unauthenticated remote attacker to retrieve Prometheus metrics that disclose virtual host names, request volumes, error rates, latency distributions, and active connections. This issue is fixed in version 2.44.0.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 2.44.0
Event History
Frequently Asked Questions
Which deployments are affected?
Static Web Server instances through version 2.43.0 are affected when both basic authentication and the metrics feature are enabled. Deployments without that combination are not described as affected.
What does an attacker need to exploit this issue?
An unauthenticated remote attacker only needs to make a request to the /metrics endpoint. User interaction and prior privileges are not required.
What information could be exposed?
The endpoint can disclose Prometheus metrics including virtual host names, request volumes, error rates, latency distributions, and active connection counts. The reported impact is limited to confidentiality.
What should be done if the affected configuration is in use?
Upgrade Static Web Server to version 2.44.0, which fixes the issue. Until upgrading, do not rely on basic authentication to restrict access to /metrics when the metrics feature is enabled.