CVE-2026-113726
published 2026-10-20CVE-2026-113726: 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…
PriorityP343high7.8CVSS 3.1
AVLACLPRNUIRSUCHIHAH
EPSS
0.26%
18.0th percentile
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.
Affected
23 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| ansible-automation-platform-26 | controller-rhel9 | — | — |
| ansible-automation-platform-26 | lightspeed-chatbot-rhel9 | — | — |
| ansible-automation-platform-27 | controller-rhel9 | — | — |
| debian | python-virtualenv | — | — |
| devspaces | udi-rhel9 | — | — |
| openshift-lightspeed | lightspeed-service-api-rhel9 | — | — |
| pypa | virtualenv | < 21.14.4 | 21.14.4 |
| rhai-early-access | docling-serve-cuda-rhel9 | — | — |
| rhoai | odh-feature-server-rhel9 | — | — |
| rhoai | odh-kserve-agent-rhel9 | — | — |
| rhoai | odh-kserve-controller-rhel9 | — | — |
| rhoai | odh-kserve-router-rhel9 | — | — |
| rhoai | odh-kserve-storage-initializer-rhel9 | — | — |
| rhoai | odh-ta-lmes-job-rhel9 | — | — |
| rhoai | odh-training-rocm64-torch28-py312-rhel9 | — | — |
| rhoai | odh-trustyai-nemo-guardrails-server-rhel9 | — | — |
| rhoai | odh-workbench-codeserver-datascience-cpu-py312-rhel9 | — | — |
| rhoai | odh-workbench-jupyter-datascience-cpu-py312-rhel9 | — | — |
| rhoai | odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9 | — | — |
| satellite | iop-advisor-backend-rhel9 | — | — |
| satellite | iop-host-inventory-rhel9 | — | — |
| satellite | iop-yuptoo-rhel9 | — | — |
| virtualenv | virtualenv | >= 0 < 21.14.4 | 21.14.4 |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
vendor_redhat7.8HIGH
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GHSA
virtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST
ghsa·2026-10-21
CVE-2026-113726 [HIGH] CWE-116 virtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST
virtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST
### Impact
zsh users activate an environment with the bash `activate` script, which puts the environment name into `PS1`. Since
21.13.0 the script escapes backslashes, dollar signs and backticks in that name, but only when `BASH_VERSION` is set, so
zsh gets the raw value. With the `PROMPT_SUBST` option set, zsh runs parameter expansion, command substitution and
arithmetic expansion on `PS1` each time it draws the prompt. A name that contains `$(...)`, backticks or `${...}` then
runs as commands in the user's shell, once per prompt.
The name comes from the environment directory, or from `--prompt` or `VIRTUALENV_PROMPT`. After you create an
environment with:
```console
$ virtualenv 'x$(touch PWNED)y'
``
Red Hat
virtualenv: virtualenv: Arbitrary command execution via unescaped prompt variables in zsh
vendor_redhat·2026-10-20·CVSS 7.8
CVE-2026-113726 [HIGH] CWE-78 virtualenv: virtualenv: Arbitrary command execution via unescaped prompt variables in zsh
virtualenv: virtualenv: Arbitrary command execution via unescaped prompt variables in zsh
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 comma
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-10-20
Published