CVE-2026-113776

virtualenv activation scripts run code from a path that contains a placeholder name

Published Oct 20, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-8rjx-v5ww-45pp virtualenv activation scripts run code from a path that contains a placeholder name
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Pypa
Pypa virtualenv
Vendors & Products Pypa
Pypa virtualenv
Type Values Removed Values Added
Description 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.
Title virtualenv activation scripts run code from a path that contains a placeholder name
Weaknesses CWE-78
CWE-94
References
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Oct 28, 2026, 2:54 PM
Reserved
Oct 20, 2026, 5:39 PM
Status
Awaiting Analysis
Published
Oct 20, 2026, 10:19 PM
Modified
Oct 28, 2026, 3:17 PM
Severity
Important
Public date
Oct 20, 2026, 10:03 PM