CVE-2026-49191: Exposed Hard-coded M3WebServer Backend API Key
The production build of the M3WebServer hard-codes its backend API keys, which can be easily intercepted through verbose error handling pages.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Remove hard-coded backend API keys from the production build. Load API keys at runtime from a secure configuration source (environment variables, secret manager, or similar) rather than embedding them in source code or build artifacts.
M3WebServer hard-coded backend API key = removed from code; use secure configuration - Configuration
Disable verbose error handling pages and debug output in production to prevent sensitive information (including API keys) from being exposed in error responses.
M3WebServer verbose error handling = disabled - Compensating control
Until code changes are deployed, restrict access to error pages and debugging endpoints (for example via firewall rules, WAF, or IP allowlists) to limit exposure of sensitive information.
- Operational
Rotate all backend API keys that were hard-coded or could have been exposed and revoke any keys that may have been compromised before deploying fixes.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-49191?
CVE-2026-49191 has a critical severity rating of 9.3.
What is CVE-2026-49191 about?
CVE-2026-49191 relates to the M3WebServer's hard-coded backend API keys that are exposed due to verbose error handling.
How do I fix CVE-2026-49191?
To fix CVE-2026-49191, remove the hard-coded API key from the production build and implement a secure key management process.
What are the risks associated with CVE-2026-49191?
The risks associated with CVE-2026-49191 include unauthorized access and potential data breaches due to exposed API keys.
How does CVE-2026-49191 affect M3WebServer users?
CVE-2026-49191 poses a significant threat to M3WebServer users by allowing attackers to exploit exposed API keys for malicious purposes.