CVE-2026-113776 — virtualenv activation scripts run code from a path that contains a placeholder name
virtualenv is a tool for creating isolated virtual python environments. From 20.26.6 until 21.14.2, ViaTemplateActivator.instantiate_template() replaces placeholders one key at …
Published: 2026-10-20 · CVSS: 7.8 · CVSS 3.1
virtualenv is a tool for creating isolated virtual python environments. From 20.26.6 until 21.14.2, ViaTemplateActivator.instantiate_template() replaces placeholders one key at a time across the complete activation template, so trigger names such as __VIRTUAL_NAME__, __VIRTUAL_ENV__, or __VIRTUAL_PROMPT__ inside an already substituted and quoted environment path or prompt can be replaced during a later pass. The later value's quoting can close the earlier literal and execute the remaining path when a user activates the environment through bash, fish, xonsh, or activate_this.py. The distinct csh prompt-display token __VIRTUAL_PROMPT_DISPLAY_TCSH__ can instead break the generated script without establishing command execution. The attacker must influence the destination path or --prompt, and a value without a relevant placeholder name does not trigger this mechanism. This issue is fixed in version 21.14.2.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7