Symlink Attack Affecting virtualenv package, versions [21.14.8,21.14.9)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-VIRTUALENV-21282482
- published21 Oct 2026
- disclosed20 Oct 2026
- creditAnthropic's OSS Scanner
Introduced: 20 Oct 2026
NewCVE-2026-113724 (opens in a new tab)How to fix?
Upgrade virtualenv to version 21.14.9 or higher.
Overview
Affected versions of this package are vulnerable to Symlink Attack via the onerror handler in src/virtualenv/util/path/_sync.py, which previously called os.chmod on a path without first checking whether it is a symbolic link. On Windows, when a read-only file cannot be deleted during a tree removal, the handler widened the file's permissions using os.chmod before retrying the deletion. Because no link check was performed, an attacker who can place a symlink at the target path can cause the handler to widen the permissions of the symlink's target, leading to unauthorized modification of file attributes and potential information disclosure or integrity impact.
Note: This is only exploitable if the attacker can traverse the target's parent directories to place a symlink at the affected path.