CVE-2026-113721

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, ViaTemplateActivator._generate() removes an existing output only when Path.exists() is true, allowing a dangling symlink to survive and redirect generated activation content, while PyEnvCfg.write() opens pyvenv.cfg without first replacing an existing symbolic or hard link. Another local account that prepares final entries inside the destination can therefore cause environment creation to create or overwrite files outside the requested tree with constrained virtualenv-generated content and the invoking user's permissions. The destination parent must remain controlled by the environment owner during creation; concurrent parent-directory replacement is a separate concern. This issue is fixed in version 21.14.9.

CVSS v3 4.5 MEDIUM

4.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.0 / Impact : 3.4

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/pypa/virtualenv/commit/d25f28699eefb1fc34a251e5adf2b5de844c36cd
https://github.com/pypa/virtualenv/pull/3431
https://github.com/pypa/virtualenv/releases/tag/21.14.9
https://github.com/pypa/virtualenv/security/advisories/GHSA-558c-9hv2-4prj

Configurations

No configuration.

History

20 Oct 2026, 20:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-20 20:17

Updated : 2026-10-28 17:17

NVD link : CVE-2026-113721

Mitre link : CVE-2026-113721

CVE.ORG link : CVE-2026-113721

JSON object : View

Products Affected

No product.

CWE

CWE-59

Improper Link Resolution Before File Access ('Link Following')

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