CVE-2026-76227 in Renovate
Summary
by MITRE • 08/19/2026
Renovate versions from 42.68.1 before 42.96.3 (and from 42.68.1 before 43.4.4), including corresponding Docker images (renovate/renovate, mend/renovate-ce, renovate-ee-server, renovate-ee-worker >=13.3.0 <13.6.0), fail to restrict environment variables to an allowlist when spawning child processes. As a result, child processes (e.g. npm install, postUpgradeTasks, postUpdateOptions) gain full access to all environment variables of the Renovate process, allowing insider or outside attackers to exfiltrate secrets accessible to the Renovate deployment.
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Analysis
by VulDB Data Team • 08/19/2026
The vulnerability identified in Renovate versions ranging from 42.68.1 up to but not including 42.96.3, as well as versions from 42.68.1 before 43.4.4, represents a critical security flaw related to environment variable handling during the execution of child processes. This issue also affects corresponding Docker images such as renovate/renovate, mend/renovate-ce, and specific Enterprise Edition variants like renovate-ee-server and renovate-ee-worker versions 13.3.0 through 13.5.x. The core technical flaw lies in the failure to restrict environment variables passed to child processes via an allowlist mechanism. Instead of filtering or whitelisting only necessary variables, Renovate passes the entire parent process environment to spawned subprocesses such as npm install commands, postUpgradeTasks, and postUpdateOptions configurations. This design oversight creates a significant attack surface where sensitive information stored in the host environment is inadvertently exposed to external scripts and tools executed by the automation tool.
From an operational perspective, this lack of isolation allows any code or script invoked during the update process to access all environment variables present in the Renovate container or host system. In typical CI/CD pipelines or automated repository management setups, these environments often contain high-value secrets such as API keys, database credentials, cloud provider tokens, and private SSH keys used for authentication with version control platforms like GitHub, GitLab, or Bitbucket. An attacker who can influence the update configuration files, such as package.json or renovate.json, could inject malicious postUpgradeTasks or modify dependencies to trigger specific npm scripts that exfiltrate these secrets. This capability effectively bypasses standard security boundaries within the automation pipeline, turning a routine dependency management task into a vector for credential theft and further lateral movement within the organization's infrastructure.
This vulnerability aligns with CWE-798: Use of Hard-coded Credentials when considering how secrets are exposed via environment variables that were intended to be isolated from untrusted code execution contexts. It also maps closely to MITRE ATT&CK technique T1053: Scheduled Task/Job, specifically the local scheduling aspect where child processes act as scheduled tasks executing under the privileges and context of the parent Renovate process. Furthermore, it relates to CWE-200: Exposure of Sensitive Information to an Unauthorized Actor, as the unfiltered environment variables constitute sensitive information that is made accessible to unauthorized entities capable of manipulating the update configuration. The severity is heightened by the fact that many organizations rely on Renovate for automated security updates, meaning the tool itself becomes a trusted conduit for data exfiltration if compromised through malicious dependency configurations or insider threats with write access to repository settings.
Mitigation strategies must focus on implementing strict environment variable filtering at the application level before spawning any child processes. Developers and maintainers should enforce an allowlist approach where only explicitly defined, non-sensitive variables are passed to subprocesses such as npm install scripts. For users currently running affected versions, immediate upgrades to version 42.96.3 or later, or 43.4.4 and above, are required to resolve the issue within the codebase. In environments where upgrading is not immediately feasible, operational mitigations include removing sensitive secrets from the environment variables available to Renovate containers, utilizing dedicated secret management solutions like HashiCorp Vault or AWS Secrets Manager that inject credentials at runtime in a controlled manner rather than relying on broad environment variable inheritance. Additionally, auditing postUpgradeTasks and postUpdateOptions configurations for any custom scripts is essential to ensure no malicious code can exploit this exposure vector while waiting for the patch deployment.