CVE-2026-114109 in astral-sh
Summary
by MITRE • 10/21/2026
uv before 0.11.15 contains a path traversal vulnerability that allows malicious wheels to write files outside the scripts directory via crafted console_scripts or gui_scripts entry point names. Attackers who induce users to install a malicious wheel can place executables in PATH directories, shadowing or overwriting existing binaries for code execution.
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Analysis
by VulDB Data Team • 10/21/2026
The vulnerability identified in uv versions prior to 0.11.15 represents a critical path traversal flaw within the package installation mechanism, specifically affecting how entry points are processed during wheel installation. This security issue stems from insufficient validation of file paths associated with console_scripts and gui_scripts metadata entries contained within Python distribution packages. When a user installs a maliciously crafted wheel archive, the installer fails to properly sanitize or restrict the target directory structure for these executable scripts. Consequently, an attacker can manipulate the entry point names to include relative path sequences that escape the intended installation sandbox, typically the local site-packages or bin directories where uv normally confines installed executables.
This technical flaw allows for arbitrary file write operations outside of the designated script directory. By embedding characters such as ../ in the console_scripts or gui_scripts definitions within the wheel's metadata, an attacker can direct the installer to place executable files into parent directories or other system locations that are accessible via the user's PATH environment variable. This capability transforms a standard package installation process into a vector for arbitrary code execution, bypassing typical sandboxing expectations associated with Python packaging tools. The vulnerability exploits the trust users implicitly place in installed packages and the automated nature of dependency resolution systems like uv.
The operational impact of this vulnerability is severe, as it enables privilege escalation through binary shadowing or overwriting. If an attacker can induce a user to install their malicious wheel, they can plant executables in directories that appear earlier in the PATH than legitimate system binaries. For instance, by placing a trojanized version of common utilities like ls, cp, or ssh into /usr/local/bin or similar locations, the malware will execute whenever these commands are invoked by the user or other applications. This technique allows for persistent access and potential data exfiltration without requiring elevated privileges at the time of installation, relying instead on the execution context of subsequent legitimate system activities.
From a classification perspective, this vulnerability aligns with CWE-22: Improper Limitation of a Pathname to a Restricted Directory, as it involves failing to restrict file writes to an expected location. It also relates to CWE-94: Improper Control of Generation of Code (Code Injection) because the malicious wheel effectively injects executable code into the system environment through legitimate packaging channels. In terms of adversary tactics, this aligns with MITRE ATT&CK techniques such as T1059 Command and Scripting Interpreter for establishing initial access via trusted tools, and potentially T1036 Masquerading if the planted binaries mimic legitimate system files to evade detection by users or security monitoring solutions.
Mitigation strategies primarily involve upgrading uv to version 0.11.15 or later, where this path traversal issue has been addressed through stricter input validation and canonicalization of file paths before writing. Organizations should enforce strict policies regarding the installation of Python packages from untrusted sources, utilizing virtual environments to isolate dependencies and limit potential damage scope. Additionally, implementing application whitelisting can prevent unauthorized executables placed in PATH directories from running, providing a defense-in-depth layer against this type of binary shadowing attack. Regular auditing of installed packages and monitoring for unusual file creation events in system directories are also recommended practices to detect such compromises early.