CVE-2026-113776: high-severity vulnerability in pypa virtualenv
virtualenv activation scripts run code from a path that contains a placeholder name
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.8epss 0.3%
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.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Affected products
pypa · virtualenvRelated CVEs — pypa virtualenv
In the same product, most dangerous first.
CVE-2026-113726HIGHvirtualenv activate runs commands from the environment name in zsh with PROMPT_SUBSTEPSS 0.3%CVE-2026-113717LOWvirtualenv: Pip seeding with download omits wheel digest verificationEPSS 0.3%CVE-2026-113722HIGHvirtualenv: Generated POSIX console launchers interpret destination paths as shell syntaxEPSS 0.3%CVE-2026-115586HIGHvirtualenv: Bash activator leaves the --prompt value unescaped in PS1 when promptvars is off, so prompt expansion later executes it (regression in 21.14.9)EPSS 0.3%CVE-2026-113725HIGHvirtualenv bash activate runs commands from an environment name with a backslash before $EPSS 0.3%CVE-2026-113714LOWvirtualenv: Downloaded wheel selection and caching precede verificationEPSS 0.2%