virtualenv bash and fish activation scripts execute commands embedded in paths

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-2026-102925: 0.16% estimated exploitation activity in the next 30 days; percentile 5.02 (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 The generated activate (bash/zsh) and activate.fish scripts interpolate a shlex.quote-ed value into a position that quotes it a second time. The extra quotes terminate the quoted run early and leave part of the value parsed as shell code, so a path containing shell metacharacters runs commands when a user sources the activation script. activate is affected through the virtual environment's own path, on the branch that reports a relocated environment: For a destination named x'$(id)'y, shlex.quote emits 'x'"'"'$(id)'"'"'y'. The inner " closes the enclosing double quote and $(id) is left unquoted. Backtick and ; payloads reach the same result. This branch runs whenever the recorded path is absent, which is the normal case for a virtual environment copied or distributed to another machine. activate.fish is affected through the interpreter's Tcl/Tk library paths: shlex.quote already returns '/tcl/(cmd)/lib', so the rendered line is ''/tcl/(cmd)/lib''. fish concatenates the…

Published by the source

1 Oct 2026, 15:09 UTC

Last modified by the source

6 Oct 2026, 15:25 UTC

Source last checked

26 Oct 2026, 13:54 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-p58f-9548-mpm2

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-p58f-9548-mpm2

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-p58f-9548-mpm2

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# Patch Next advisory brief: CVE-2026-102925

Advisory: virtualenv bash and fish activation scripts execute commands embedded in paths
IDs: CVE-2026-102925, GHSA-p58f-9548-mpm2
Record: https://patchnext.com/advisories/cve-2026-102925 (revision 3, source checked 26 Oct 2026, 13:54 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 21.7.13. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI virtualenv: affected <= 21.7.12; fixed in 21.7.13

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

## 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-p58f-9548-mpm2 (GitHub-reviewed advisory GHSA-p58f-9548-mpm2 lists affected ranges: PyPI virtualenv >=0 <=21.7.12)
- Verified: https://osv.dev/vulnerability/GHSA-p58f-9548-mpm2 (OSV record GHSA-p58f-9548-mpm2 lists affected ranges: PyPI virtualenv >=0 <21.7.13 (fixed))

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