virtualenv bash activate runs commands from an environment name with a backslash before $

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.8 · CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-113725: 0.26% estimated exploitation activity in the next 30 days; percentile 18.27 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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 bash draws the prompt.

Affected area `src/virtualenv/activation/bash/activate.sh`, the block that prepends the environment name to `PS1`.

Attacker-controlled input The environment name: the environment directory's name, or the `--prompt` or `VIRTUALENV_PROMPT` value. An attacker needs to influence it, for example through a CI job or wrapper tool that passes a branch, project or job name through, or a directory in a cloned repository or unpacked archive. `--prompt .` takes the current directory's name.

Details bash handles `PS1` in two passes each time it draws the prompt: it first decodes backslash prompt escapes, turning `\\` into `\` and `\$` into `$` (or `#` for root), and then runs parameter expansion, command substitution…

Published by the source

21 Oct 2026, 16:49 UTC

Last modified by the source

29 Oct 2026, 10:55 UTC

Source last checked

30 Oct 2026, 07:20 UTC

1. Revision 5 · amended · 30 Oct 2026

   Amended from osv record BIT-virtualenv-2026-113725

2. Revision 4 · amended · 30 Oct 2026

   Amended from osv record GHSA-vxj4-q4g9-crj7

3. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-vxj4-q4g9-crj7

4. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-vxj4-q4g9-crj7

5. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-vxj4-q4g9-crj7

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# Patch Next advisory brief: CVE-2026-113725

Advisory: virtualenv bash activate runs commands from an environment name with a backslash before $
IDs: CVE-2026-113725, GHSA-vxj4-q4g9-crj7
Record: https://patchnext.com/advisories/cve-2026-113725 (revision 5, source checked 30 Oct 2026, 07:20 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: virtualenv 21.14.7; virtualenv 21.14.7. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI virtualenv: affected < 21.14.7; fixed in 21.14.7
- Bitnami virtualenv: affected < 21.14.7; fixed in 21.14.7

## Suggested inspection (read-only)
- `python -m pip show virtualenv`: prints the installed version. Run with the environment that serves production active.
- Bitnami virtualenv: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on virtualenv.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-vxj4-q4g9-crj7 (GitHub-reviewed advisory GHSA-vxj4-q4g9-crj7 lists affected ranges: PyPI virtualenv >=0 <=21.14.6)
- Verified: https://osv.dev/vulnerability/GHSA-vxj4-q4g9-crj7 (OSV record GHSA-vxj4-q4g9-crj7 lists affected ranges: PyPI virtualenv >=0 <21.14.7 (fixed))
- Verified: https://osv.dev/vulnerability/BIT-virtualenv-2026-113725 (OSV record BIT-virtualenv-2026-113725 lists affected ranges: Bitnami virtualenv >=0 <21.14.7 (fixed))

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