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TI-2026-78529 Aliases CVE-2026-113726GHSA-5vjq-rrrf-7h2q

Command execution in virtualenv activate script under zsh

Priority LOW 36CWE-116Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 5 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-78.

Summary

virtualenv before 21.14.4 has an activate script that leaves the environment name unescaped for zsh. With PROMPT_SUBST enabled in zsh, command, parameter or arithmetic expansion syntax in an environment directory name, --prompt or VIRTUALENV_PROMPT value runs commands in the user's shell each time the prompt is drawn (CWE-78). An attacker who can influence those values can trigger this when a user activates the environment.

Written with Claude Haiku 5.5 from the sources below · 2026-11-07

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00345 28th percentileScored 2026-11-07
Fix Partial virtualenv (pypa): 21.14.4virtualenv (PyPI): 21.14.4Red Hat: 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
pypavirtualenvbefore 21.14.421.14.4Patch availableCNA
—virtualenv (PyPI)before 21.14.421.14.4Patch availableGHSA-5vjq-rrrf-7h2q
  • virtualenv Vendorpypa Affected before 21.14.4 Fixed in 21.14.4 Patch available CNA
  • virtualenv (PyPI) Vendor— Affected before 21.14.4 Fixed in 21.14.4 Patch available GHSA-5vjq-rrrf-7h2q

Remediation

Upgrade virtualenv to 21.14.4, the fixed version listed for PyPI. Red Hat lists OpenShift Lightspeed as affected with no fix planned, and Red Hat Ansible Automation Platform 2, Red Hat OpenShift AI (RHOAI), Red Hat OpenShift Dev Spaces and Red Hat Satellite 6 as affected with no fix available.

Written with Claude Haiku 5.5 from the sources below · 2026-11-07

  • Fix · CNA virtualenv (pypa) Fixed in 21.14.4
  • Fix · GHSA-5vjq-rrrf-7h2q virtualenv (PyPI) Fixed in 21.14.4 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
OpenShift LightspeedAffectedNo fix planned: Will not fix
Red Hat Ansible Automation Platform 2AffectedNo fix yet
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Red Hat OpenShift Dev SpacesAffectedNo fix yet
Red Hat Satellite 6AffectedNo fix yet
Not affected: 3 products
  • Red Hat Ansible Automation Platform 2
  • Red Hat OpenShift AI (RHOAI)
  • Red Hat OpenShift Container Platform 4

Timeline

  1. 2026-10-21 Threatist record created from CVE-2026-113726
  2. 2026-10-21 Affected versions changed · Red Hat
  3. 2026-10-21 CVSS score added · Red Hat
  4. 2026-10-21 Alias added: GHSA-5vjq-rrrf-7h2q
  5. 2026-10-21 Fix available: PyPI/[email protected] · GHSA-5vjq-rrrf-7h2q
  6. 2026-10-21 CVSS score added · GHSA-5vjq-rrrf-7h2q
  7. 2026-10-21 Weakness changed · GHSA-5vjq-rrrf-7h2q
  8. 2026-10-21 5 new references · GHSA-5vjq-rrrf-7h2q
  9. 2026-10-22 Priority changed: MEDIUM → LOW
  10. 2026-10-22 Affected versions changed · Red Hat
  11. 2026-10-27 CISA SSVC decision points changed
  12. 2026-11-02 Affected versions changed · Red Hat
  13. 2026-11-03 Affected versions changed · Red Hat
  14. 2026-11-07 Affected versions changed · Red Hat

References

Advisory 1

Other 4

  • TI-2025-29803 setuptools has a path traversal vulnerability in PackageIndex.download that leads to Arbitrary File Write CVSS 4.0HIGH 7.7
  • TI-2024-05888 Remote Code Execution in pypa/setuptools CVSS 3.0HIGH 8.8
  • TI-2026-78525 Shell command injection in virtualenv generated POSIX launchers CVSS 3.1HIGH 7.8
  • TI-2026-78526 Command injection in virtualenv bash activation prompt CVSS 4.0HIGH 7.1
  • TI-2026-78521 Code injection in virtualenv Xonsh activation script CVSS 4.0HIGH 7.1
  • TI-2026-19377 wheel Allows Arbitrary File Permission Modification via Path Traversal CVSS 3.1HIGH 7.1
See all 36 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences