Description
virtualenv is a tool for creating isolated virtual python environments. Prior to version 20.36.1, TOCTOU (Time-of-Check-Time-of-Use) vulnerabilities in virtualenv allow local attackers to perform symlink-based attacks on directory creation operations. An attacker with local access can exploit a race condition between directory existence checks and creation to redirect virtualenv's app_data and lock file operations to attacker-controlled locations. This issue has been patched in version 20.36.1.
Scores
CVSS v3
4.5
EPSS
0.0001
EPSS Percentile
2.6%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-362
CWE-59
Status
published
Products (2)
pypi/virtualenv
0 - 20.36.1PyPI
virtualenv/virtualenv
< 20.36.1
Published
Jan 10, 2026
Tracked Since
Feb 18, 2026