CVE-2026-113776
published 2026-10-20CVE-2026-113776: virtualenv is a tool for creating isolated virtual python environments. From 20.26.6 until 21.14.2, ViaTemplateActivator.instantiate_template() replaces…
PriorityP342high7.8CVSS 3.1
AVLACLPRNUIRSUCHIHAH
EPSS
0.27%
18.9th percentile
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.
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 | — | — |
| 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 | >= 20.26.6 < 21.14.2 | 21.14.2 |
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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Red Hat
virtualenv: virtualenv: Arbitrary command execution via sequential placeholder substitution in activation templates
vendor_redhat·2026-10-20·CVSS 7.8
CVE-2026-113776 [HIGH] CWE-94 virtualenv: virtualenv: Arbitrary command execution via sequential placeholder substitution in activation templates
virtualenv: virtualenv: Arbitrary command execution via sequential placeholder substitution in activation templates
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 genera
GHSA
virtualenv activation scripts run code from a path that contains a placeholder name
ghsa·2026-10-21
CVE-2026-113776 [HIGH] CWE-78 virtualenv activation scripts run code from a path that contains a placeholder name
virtualenv activation scripts run code from a path that contains a placeholder name
### Impact
`ViaTemplateActivator.instantiate_template` replaces the placeholders in an activation template one key at a time, each across the whole text. When a value that it already substituted and quoted contains the name of a later placeholder, the later pass rewrites that name inside the quoted literal. The inserted value brings its own quotes, which close the outer literal, and the rest of the path runs as code when a user activates the environment.
`__VIRTUAL_NAME__` holds the environment's directory name, so a destination such as `A__VIRTUAL_NAME__B/x'$(touch PWNED)'y` is enough. In the default `activate` for bash, the `VIRTUAL_ENV` line renders as:
```sh
VIRTUAL_ENV='/tmp/t/A'x'"'"'$(touch PWNED
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-10-20
Published