A security issue was discovered in ingress-nginx where the `nginx.ingress.kubernetes.io/auth-method` Ingress annotation can be used to inject configuration into nginx. This can lead to arbitrary code execution in the context of the ingress-nginx controller, and disclosure of Secrets accessible to the controller. (Note that in the default installation, the controller can access all Secrets cluster-wide.)
With a CVSS score of 8.8, this vulnerability is classified as high severity. The impact is significant because it could allow unauthorized access to sensitive information and potentially enable attackers to execute arbitrary code. Given its high exploitability, organizations need to prioritize addressing this vulnerability.
Organizations should prioritize patching immediately to mitigate the risks associated with this vulnerability. The default installation of the ingress-nginx controller facilitates access to all Secrets within the cluster, amplifying the potential damage.
The urgency for remediation is compounded by the fact that this vulnerability affects systems using ingress-nginx, which is widely utilized in Kubernetes deployments. Organizations utilizing this technology must act swiftly to protect their infrastructures.
Vulnerability Details
This vulnerability allows unauthorized configuration injection into nginx through the Ingress annotation. The affected component is ingress-nginx, which is commonly used in Kubernetes environments. The vulnerability was published on February 3, 2026, and is classified under CWE-20: Improper Input Validation.
The CVSS score of 8.8 indicates a high severity level, making it critical for organizations to understand the potential impacts and act accordingly. The vulnerability can lead to high confidentiality, integrity, and availability impacts due to the nature of the access granted to the ingress-nginx controller.
Technical Analysis
The root cause of this vulnerability stems from the misconfiguration of the `nginx.ingress.kubernetes.io/auth-method` annotation, which allows attackers to inject malicious configurations. The attack vector is network-based, meaning attackers can exploit this vulnerability remotely without needing physical access to the target system.
The attack complexity is classified as low, with low privileges required to execute an attack. No user interaction is needed, making this vulnerability particularly dangerous. The potential impacts are severe, affecting confidentiality, integrity, and availability, as unauthorized access could lead to data exposure and system compromise.
Risk & Impact Analysis
Risk to organizations includes unauthorized access to sensitive Secrets and the ability to execute arbitrary code within the ingress-nginx controller context. This could lead to extensive data breaches and system integrity issues. The potential blast radius is significant, particularly for organizations with sensitive data and those reliant on cloud-native architectures.
Given the high CVSS score of 8.8 and the potential for exploitation, organizations should address this vulnerability in their priority patch cycle. The low attack complexity and requirement for no user interaction further emphasize the need for immediate action to secure environments.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions prior to vendor patch are affected. Organizations using ingress-nginx should ensure they are running the latest version to mitigate this vulnerability.
Mitigation & Remediation
To mitigate this vulnerability, organizations should apply the latest patches for ingress-nginx immediately. If a patch is unavailable, consider implementing configuration hardening practices that restrict access to sensitive configurations. Organizations should also monitor their ingress-nginx logs for any unusual activities.
For comprehensive security assessments, organizations may refer to our application security assessment services to identify and remediate vulnerabilities across your systems.
Detection Guidance
Organizations should monitor logs for indicators of compromise, such as unexpected changes to nginx configurations or unauthorized accesses to Secrets. It is also advisable to detect behavioral anomalies that could indicate exploitation attempts.
AppSecure Threat Intelligence Insight
This vulnerability exemplifies the risks associated with misconfigurations in cloud-native environments. Security teams should focus on continuous monitoring and periodic assessments to catch such vulnerabilities early. The incident underscores the importance of adhering to security best practices, such as regular updates and configuration reviews.
For more insights on vulnerability management, organizations can explore our vulnerability management program design. Additionally, understanding the penetration testing methodology is critical, which can be found in our penetration testing methodology article.
Lastly, organizations should familiarize themselves with best practices in security testing to ensure a robust defense against potential threats.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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