Stale file permissions in virtualenv seeded environments
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- Passive
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- Low · High · Low
- Fix status
- Partial Red Hat: 6 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat.
Summary
virtualenv before 21.14.9 uses shutil.copy() in its app-data seeder, so cached package files keep the permissions they had when the cache was built (CWE-732). A cache populated under a permissive umask can leave files writable by another local account in a later environment that others can traverse. A local user with low privileges can then modify package code such as pip/__init__.py, which the environment owner executes.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, the app-data copy seeder uses shutil.copy() to copy cached package files into later environments, causing cached source modes to override the current run's umask. A cache populated under a permissive umask can therefore produce files writable by another local account in a later traversable environment, allowing package code such as pip/__init__.py to be modified and executed by the environment owner. The attacker cannot force the earlier umask, and a private destination parent prevents access. This issue is fixed in version 21.14.9.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| pypa | virtualenv | before 21.14.9 | 21.14.9 | Patch available | CNA |
| — | virtualenv (PyPI) | before 21.14.9 | 21.14.9 | Patch available | GHSA-fc2g-4w5p-6whm |
- virtualenv Vendorpypa Affected before 21.14.9 Fixed in 21.14.9 Patch available CNA
- virtualenv (PyPI) Vendor— Affected before 21.14.9 Fixed in 21.14.9 Patch available GHSA-fc2g-4w5p-6whm
Remediation
Upgrade the PyPI virtualenv package to 21.14.9, which fixes the flaw. Red Hat lists these products as affected with no plan available: OpenShift Lightspeed, Red Hat Ansible Automation Platform 2, Red Hat OpenShift AI (RHOAI), Red Hat OpenShift Container Platform 4, Red Hat OpenShift Dev Spaces and Red Hat Satellite 6.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA virtualenv (pypa) Fixed in 21.14.9
- Fix · GHSA-fc2g-4w5p-6whm virtualenv (PyPI) Fixed in 21.14.9 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| OpenShift Lightspeed | Affected | No fix yet: Fix deferred |
| Red Hat Ansible Automation Platform 2 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift AI (RHOAI) | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Dev Spaces | Affected | No fix yet: Fix deferred |
| Red Hat Satellite 6 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-21 Threatist record created from CVE-2026-113720
- 2026-10-21 Affected versions changed · Red Hat
- 2026-10-21 CVSS score added · Red Hat
- 2026-10-21 CISA SSVC decision points changed
- 2026-10-23 Alias added: GHSA-fc2g-4w5p-6whm
- 2026-10-23 Fix available: PyPI/[email protected] · GHSA-fc2g-4w5p-6whm
- 2026-10-23 CVSS score added · GHSA-fc2g-4w5p-6whm
- 2026-10-23 Weakness changed · GHSA-fc2g-4w5p-6whm
- 2026-10-23 6 new references · GHSA-fc2g-4w5p-6whm
References
More pypa vulnerabilities
- 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
Sources
- CVE-2026-113720 · CVE Program
- CVE-2026-113720 · NVD
- FIRST EPSS
- GHSA-fc2g-4w5p-6whm · GitHub Advisory Database · CC BY 4.0
- CVE-2026-113720 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences