CVE-2026-113732

virtualenv activate.fish runs commands from a path or prompt with a backslash before a quote

State: Published
Severity: 7.8 High
Published: Oct 20, 2026
Updated: Oct 27, 2026
Reserved: Oct 20, 2026

Description

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.2, FishActivator inherits ViaTemplateActivator.quote(), which uses POSIX shlex.quote() even though fish interprets backslashes and single quotes differently. An attacker-influenced environment path, --prompt, or VIRTUALENV_PROMPT value containing a backslash before a quote can therefore terminate the generated fish literal and execute command substitution when the user sources activate.fish. This issue is fixed in version 21.14.2.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H	GitHub_M

Weaknesses

CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-116 Improper Encoding or Escaping of Output

Affected Products

Product	Versions
virtualenvpypa	< 21.14.2Affected

References

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