CVE-2026-50187 in Oh My Zsh
Summary
by MITRE • 08/18/2026
Oh My Zsh is a community-driven framework for managing Zsh configuration. Prior to 2026-05-28, the dotenv plugin in plugins/dotenv/dotenv.plugin.zsh passes ZSH_DOTENV_FILE to source after a directory change into a folder containing a .env file, allowing syntactically valid shell commands in the file to execute with the current account's privileges, including without a prompt when ZSH_DOTENV_PROMPT=false or after the default prompt accepts an empty Enter response. This issue is fixed in versions released after 2026-05-28.
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Analysis
by VulDB Data Team • 08/19/2026
The vulnerability identified within Oh My Zsh affects the dotenv plugin, which is designed to load environment variables from .env files into the shell session. The core technical flaw lies in how the plugin handles file sourcing relative to directory changes and user interaction prompts. Specifically, when a user navigates into a directory containing a .env file, the plugin automatically sources this file by passing its path to the source command without sufficient validation of the file's contents or context. This mechanism allows an attacker who can influence the content of a .env file in a target directory to inject syntactically valid shell commands that will be executed with the privileges of the current user account upon navigation into that directory.
The operational impact is significant because it facilitates arbitrary code execution within the scope of the victim's permissions. The vulnerability manifests primarily through two vectors: first, when ZSH_DOTENV_PROMPT is set to false, which disables interactive confirmation, allowing immediate and silent execution of any commands present in the .env file; second, even with prompting enabled, if a user inadvertently presses Enter without providing input or accepts an empty response, the plugin proceeds to source the file. This behavior effectively turns standard directory traversal into a potential attack vector where maliciously crafted configuration files can trigger unintended command execution simply by being accessed via shell navigation commands such as cd.
From a classification perspective, this vulnerability aligns with CWE-94 Improper Control of Generation of Code or Command, commonly known as code injection, due to the untrusted input from external .env files being interpreted and executed directly by the shell interpreter. It also relates to CWE-78 Improper Neutralization of Special Elements used in an OS Command if specific characters are not escaped before sourcing. In terms of adversary tactics, this behavior mirrors techniques found in MITRE ATT&CK under T1059 Command and Scripting Interpreter, where attackers leverage legitimate system utilities or scripts to execute malicious payloads without raising immediate suspicion, particularly when the execution is triggered by routine user actions like changing directories.
Mitigation strategies should focus on restricting the scope of automatic sourcing and enhancing input validation. Users are advised to upgrade Oh My Zsh to versions released after May 28, 2026, which address this logic flaw. For environments where upgrading is not immediately feasible, administrators can mitigate risk by disabling the dotenv plugin entirely or configuring it to only source files from explicitly trusted directories rather than dynamically based on the current working directory. Additionally, enforcing strict shell options such as set -u for unset variable checking and avoiding the use of ZSH_DOTENV_PROMPT=false in untrusted environments reduces the attack surface. Security awareness training should also emphasize caution when navigating into shared or public directories that may contain configuration files with unknown origins.