Patch Forecast
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CVE-2026-113726 · GHSA-5vjq-rrrf-7h2q

virtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST

Risk score
54/100
CVSS
7.8 v3.1
Exploit chance (30 days)
0.2%
Published
20 Oct 2026

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What to know

What it is
virtualenv is a tool for creating isolated virtual python environments. Prior to 21.13.0, the bash activate script that zsh also sources leaves the environment name unescaped; from 21.13.0 until 21.14.4, it escapes backslashes, dollar signs, and backticks only when BASH_VERSION is set, so zsh receives the raw value. T…
Affected
virtualenv (pip) <= 21.14.3
Fix
Upgrade virtualenv to 21.14.4 or later.
Exploitation
No known exploitation

Story map

Story map: virtualenvTHE FLAWSTHE FIXCVE-2026-113726Virtualenv activate runscommands from theenvironment name in zsh with…CVSS 7.8 · EPSS 0%CVE-2026-113725Virtualenv bash activate runscommands from anenvironment name with a…CVSS 7.8 · EPSS 0%CVE-2026-102930Downloaded seed wheels(pip/setuptools) are notintegrity-checked before useCVSS 7.7 · EPSS 0%CVE-2026-113776Virtualenv activation scriptsrun code from a path thatcontains a placeholder nameCVSS 7.8 · EPSS 0%Upgrade virtualenv21.13.0 · 21.14.4 · 21.14.7 · 21.7.12· 21.14.2or later on your release lineWho is exposedvirtualenv (pip) <= 21.14.6YELLOW · PLAN IT INvirtualenvvirtualenv is a tool for creatingisolated virtual pythonenvironments. Prior to 21.14.7,the bash activate script escapesthe environment name for onlyone of the two passes bashmakes over PS1, so a backslash…Where it standsPublic proof of conceptCONNECTS TOSame weaknessOS command injection (CWE-78)306 other warnings in 30 days →
Story map: the flaws, the fix, how it unfolded and what it connects to. Boxes link to the record or article.

At a glance

virtualenv: Yellow, plan it in. virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.7, the bash activate script escapes the environment name for only one of the two passes bash makes over PS1, so a backslash in the name undoes the escaping and a name containing \$(...) runs as commands in the user's shell each time…

The flaws

  • CVE-2026-113726: Virtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST (CVSS 7.8 · EPSS 0%)
  • CVE-2026-113725: Virtualenv bash activate runs commands from an environment name with a backslash before $ (CVSS 7.8 · EPSS 0%)
  • CVE-2026-102930: Downloaded seed wheels (pip/setuptools) are not integrity-checked before use (CVSS 7.7 · EPSS 0%)
  • CVE-2026-113776: Virtualenv activation scripts run code from a path that contains a placeholder name (CVSS 7.8 · EPSS 0%)

The fix

Upgrade virtualenv: 21.13.0 · 21.14.4 · 21.14.7 · 21.7.12 · 21.14.2 or later on your release line

Who is exposed: virtualenv (pip) <= 21.14.6

Where it stands

  • Public proof of concept

Connects to

Why it is Yellow

  • CVSS 7.8 high
  • On your watchlist: PyPI

Affected packages

PackageEcosystemVulnerableFixed in
virtualenvpip<= 21.14.321.14.4

References

Original description

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.13.0, the bash activate script that zsh also sources leaves the environment name unescaped; from 21.13.0 until 21.14.4, it escapes backslashes, dollar signs, and backticks only when BASH_VERSION is set, so zsh receives the raw value. The script assigns that value to PS1. In zsh with PROMPT_SUBST, an attacker-influenced environment directory, --prompt, or VIRTUALENV_PROMPT value containing command, parameter, or arithmetic expansion syntax can therefore execute commands in the user's shell each time the prompt is drawn. A percent sign is separately interpreted as a zsh prompt escape but does not by itself execute commands. Plain zsh with PROMPT_SUBST disabled and bash are not affected by this mechanism. This issue is fixed in version 21.14.4.

Last activity 20 Oct 2026. Patch Forecast updates every hour.