virtualenv activation scripts run code from a path that contains a placeholder name

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-2026-113776: 0.27% estimated exploitation activity in the next 30 days; percentile 19.12 (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.

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 `AVIRTUAL_NAMEB/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)'"'"'y'B/x'"'"'$(touch PWNED)'"'"'y' ``` Sourcing that script runs `touch PWNED`. The same payload in a path without the placeholder name runs nothing. `activate.fish` runs the command the same way, and the reporter also showed Python code execution through `activate.xsh` and…

Published by the source

21 Oct 2026, 16:39 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-2026-113776

2. Revision 4 · amended · 30 Oct 2026

   Amended from osv record GHSA-8rjx-v5ww-45pp

3. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-8rjx-v5ww-45pp

4. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-8rjx-v5ww-45pp

5. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-8rjx-v5ww-45pp

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# Patch Next advisory brief: CVE-2026-113776

Advisory: virtualenv activation scripts run code from a path that contains a placeholder name
IDs: CVE-2026-113776, GHSA-8rjx-v5ww-45pp
Record: https://patchnext.com/advisories/cve-2026-113776 (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 21.14.2; virtualenv 21.14.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI virtualenv: affected >= 20.26.6, < 21.14.2; fixed in 21.14.2
- Bitnami virtualenv: affected >= 20.26.6, < 21.14.2; fixed in 21.14.2

## 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-8rjx-v5ww-45pp (GitHub-reviewed advisory GHSA-8rjx-v5ww-45pp lists affected ranges: PyPI virtualenv >=20.26.6 <=21.14.1)
- Verified: https://osv.dev/vulnerability/GHSA-8rjx-v5ww-45pp (OSV record GHSA-8rjx-v5ww-45pp lists affected ranges: PyPI virtualenv >=20.26.6 <21.14.2 (fixed))
- Verified: https://osv.dev/vulnerability/BIT-virtualenv-2026-113776 (OSV record BIT-virtualenv-2026-113776 lists affected ranges: Bitnami virtualenv >=20.26.6 <21.14.2 (fixed))

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