CVE-2025-55740

Workarounds

Users can remediate the vulnerability without upgrading by manually changing all default credentials in configuration files before deployment:

# config.yaml
auth:
  default_password: "your_strong_password_here"

# docker-compose.yml
- GF_SECURITY_ADMIN_PASSWORD=your_strong_password

Restrict access to the admin interface and use environment variables for secrets.

References

• Security Configuration Guide
• Full Security Advisory
• Library README
• README

This is a configuration vulnerability affecting nginx-defender deployments. Example configuration files
config.yaml, docker-compose.yml contain default credentials (default_password: "change_me_please", GF_SECURITY_ADMIN_PASSWORD=admin123). If users deploy nginx-defender without changing these defaults, attackers with network access could gain administrative control, bypassing security protections.

Who is impacted?
All users who deploy nginx-defender with default credentials and expose the admin interface to untrusted networks.

CVE-2025-55740 has a CVSS score of 6.5 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.5.0); upgrading removes the vulnerable code path.

Kodem intelligence

The issue is addressed in v1.5.0 and later.

Startup warnings are added if default credentials are detected.
Documentation now strongly recommends changing all default passwords before deployment.
Patched versions:
1.5.0 and later
Will be fully patched in v1.7.0 and later

1. What is CVE-2025-55740? CVE-2025-55740 is a medium-severity security vulnerability in github.com/Anipaleja/nginx-defender (go), affecting versions < 1.5.0. It is fixed in 1.5.0.
2. How severe is CVE-2025-55740? CVE-2025-55740 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/Anipaleja/nginx-defender are affected by CVE-2025-55740? github.com/Anipaleja/nginx-defender (go) versions < 1.5.0 is affected.
4. Is there a fix for CVE-2025-55740? Yes. CVE-2025-55740 is fixed in 1.5.0. Upgrade to this version or later.
5. Is CVE-2025-55740 exploitable, and should I be worried? Whether CVE-2025-55740 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-55740 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-55740? Upgrade github.com/Anipaleja/nginx-defender to 1.5.0 or later.