CVE-2025-55740

CVE-2025-55740 is a medium-severity vulnerability with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1392.

Key facts

Description

nginx-defender is a high-performance, enterprise-grade Web Application Firewall (WAF) and threat detection system engineered for modern web infrastructure. This is a configuration vulnerability affecting nginx-defender deployments. Example configuration files config.yaml and 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. The issue is addressed in v1.5.0 and later.

Frequently asked questions

What is CVE-2025-55740?
nginx-defender is a high-performance, enterprise-grade Web Application Firewall (WAF) and threat detection system engineered for modern web infrastructure. This is a configuration vulnerability affecting nginx-defender deployments. Example configuration files config.yaml and 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. The issue is addressed in v1.5.0 and later.
How severe is CVE-2025-55740?
CVE-2025-55740 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2025-55740 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-55740?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-55740 have an EU (EUVD) identifier?
Yes. CVE-2025-55740 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-25214.
When was CVE-2025-55740 published?
CVE-2025-55740 was published on 2025-08-19 and last updated on 2026-06-17.

References

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