CVE-2025-58758 is a medium-severity vulnerability affecting the TinyEnv PHP library, versions 1.0.1, 1.0.2, 1.0.9, and 1.0.10. TinyEnv is a utility used to load environment variables from a .env file into PHP applications. The vulnerability arises because TinyEnv does not require the .env file to exist when initializing environment variables. As a result, if the .env file is missing or not properly deployed, the application silently proceeds without loading expected configuration values. This improper handling of exceptional conditions (classified under CWE-703) can lead to unexpected application behavior, including the use of insecure default settings or misconfigurations that may weaken the security posture of the application. For example, missing critical environment variables such as database credentials, API keys, or security flags could cause the application to fall back to unsafe defaults or fail to enforce security controls. The vulnerability does not require user interaction or privileges to exploit and has a CVSS 3.1 base score of 5.1, reflecting low attack vector (local), low attack complexity, no privileges required, and no user interaction needed. The impact affects confidentiality and integrity but not availability. No known exploits are currently reported in the wild. The issue has been resolved in TinyEnv version 1.0.11, which enforces the presence of the .env file or otherwise prevents silent failures. Users are advised to upgrade to 1.0.11 or later. As a temporary mitigation, developers can implement manual checks to verify the existence of the .env file before initializing TinyEnv to avoid silent misconfigurations.

For European organizations, this vulnerability poses a risk primarily to PHP applications that rely on TinyEnv for environment configuration management. The silent failure to load environment variables can lead to insecure default configurations, potentially exposing sensitive data or weakening authentication and authorization mechanisms. This can result in unauthorized data access or integrity violations, especially in applications handling personal data protected under GDPR. The impact is heightened in sectors with strict compliance requirements such as finance, healthcare, and government services. While the attack vector is local, the vulnerability can be exploited by an attacker with access to the application environment, such as through compromised developer machines, CI/CD pipelines, or container environments. The lack of availability impact reduces the risk of denial-of-service, but confidentiality and integrity concerns remain significant. Since no known exploits exist yet, the window for proactive remediation is open, but organizations should prioritize patching to prevent potential exploitation as attackers may develop exploits targeting this flaw.

1. Upgrade all TinyEnv dependencies to version 1.0.11 or later immediately to ensure the vulnerability is patched. 2. Implement pre-deployment checks in CI/CD pipelines to verify the presence and correctness of the .env file before application startup. 3. Add runtime validation in the application to confirm that critical environment variables are loaded and valid, failing fast if they are missing or malformed. 4. Restrict access to the environment and deployment systems to trusted personnel and secure build environments to reduce the risk of local exploitation. 5. Conduct code reviews and security audits focusing on environment variable handling and configuration management practices. 6. Monitor application logs for unexpected configuration loads or warnings related to missing environment variables. 7. Educate development and operations teams about the importance of environment file management and the risks of silent configuration failures.