CVE-2026-113722: virtualenv: Generated POSIX console launchers interpret destination paths as shell syntax
virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, virtualenv's ScriptMakerCustom and pip pass an incompletely quoted interpreter path to distlib ScriptMaker when generating POSIX console scripts. When the path contains a space or produces a shebang longer than 127 bytes, distlib emits a /bin/sh wrapper whose double-quoted interpreter path still expands command substitutions and backticks. An attacker who influences the environment destination can therefore execute commands with the user's privileges when the user later runs a generated launcher; environment creation and activation do not trigger the command. Existing launchers are not repaired by upgrading virtualenv alone and must be regenerated, while a later independent pip installation or upgrade can reintroduce an affected launcher because pip's vendored distlib is unchanged. The virtualenv fix is released in version 21.14.9.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
virtualenvto a version that resolves this vulnerability.Fixed in 21.14.9 - Operational
Regenerate existing POSIX console launchers; upgrading virtualenv alone does not repair launchers that were already generated.
Event History
Frequently Asked Questions
What conditions are required for exploitation?
An attacker must be able to influence the virtual environment destination path so that it contains shell syntax in a path with a space or one that causes a shebang longer than 127 bytes. The user must later run a generated POSIX console launcher; creating or activating the environment alone does not execute the injected command.
What should be done after upgrading virtualenv?
Upgrade virtualenv to version 21.14.9 or later, then regenerate existing console launchers. Launchers created before the upgrade are not repaired automatically.
Can a fixed virtualenv installation still produce affected launchers?
Yes. A later independent pip installation or upgrade can reintroduce an affected launcher because pip's vendored distlib remains unchanged.