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TI-2026-78527 Aliases CVE-2026-113724GHSA-43mp-35q3-x3fq

Symlink following in virtualenv deletion recovery changes file modes

Priority MEDIUM 54CWE-59Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
Low · Low · Low
Fix status
Partial Red Hat: 6 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

virtualenv before 21.14.9 follows a symlink in its safe_delete() error handler when it changes file permissions (CWE-59). A local user who can plant a link in a read-only directory can make a target outside the destination broadly writable, provided the user owns that target and can change its mode. Another account needs to traverse the target's parent directories to use the widened mode.

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 safe_delete() deletion error handler responds to a failed removal by reading mode bits with os.lstat(path) and applying owner-write permission with os.chmod(path, ...), which follows a symlink. A planted link inside a read-only directory can therefore cause a victim-owned target outside the destination that is initially not writable by the invoking user to become broadly writable before the retry fails, provided that user owns the target and can change its mode. Another account can use the widened mode only if it can traverse the target's parent directories; root does not reach the demonstrated failure path, and the operation does not itself read the target. This issue is fixed in version 21.14.9.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00203 10th percentileScored 2026-11-07
Fix Partial virtualenv (pypa): 21.14.9virtualenv (PyPI): 21.14.9Red Hat: 6 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
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

VendorProductAffected versionsFixed inStatusSource
pypavirtualenvbefore 21.14.921.14.9Patch availableCNA
—virtualenv (PyPI)before 21.14.921.14.9Patch availableGHSA-43mp-35q3-x3fq
  • 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-43mp-35q3-x3fq

Remediation

Upgrade virtualenv to version 21.14.9, the fixed version listed for PyPI. Red Hat lists no planned fix for 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-43mp-35q3-x3fq virtualenv (PyPI) Fixed in 21.14.9 Advisory →

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
OpenShift LightspeedAffectedNo fix yet: Fix deferred
Red Hat Ansible Automation Platform 2AffectedNo fix yet: Fix deferred
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Dev SpacesAffectedNo fix yet: Fix deferred
Red Hat Satellite 6AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-21 Threatist record created from CVE-2026-113724
  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-43mp-35q3-x3fq
  5. 2026-10-21 Fix available: PyPI/[email protected] · GHSA-43mp-35q3-x3fq
  6. 2026-10-21 CVSS score added · GHSA-43mp-35q3-x3fq
  7. 2026-10-21 Weakness changed · GHSA-43mp-35q3-x3fq
  8. 2026-10-21 6 new references · GHSA-43mp-35q3-x3fq
  9. 2026-10-27 CISA SSVC decision points changed
  10. 2026-10-27 Priority changed: LOW → MEDIUM

References

Advisory 1

Other 5

  • 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