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.

The CentOS Linux 7 host has a package installed that is affected by multiple vulnerabilities as referenced in the TuxCare CENTOS7:CLSA-2026:1793888087 advisory.

  - virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, caller-supplied     prompt text can become executable syntax in the bash activation prompt. An attacker must influence the     value passed to virtualenv, and a user must subsequently activate the environment and draw the prompt.
    This vulnerability is fixed in 21.14.9. (CVE-2026-113723)

  - virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.7, the bash     activate script escapes the environment name for only one of the two passes bash makes over PS1, so a     backslash in the name undoes the escaping and a name containing \$(...) runs as commands in the user's     shell each time bash draws the prompt. This issue is fixed in version 21.14.7. (CVE-2026-113725)

  - virtualenv is a tool for creating isolated virtual python environments. Prior to 21.13.0, the bash     activate script that zsh also sources leaves the environment name unescaped; from 21.13.0 until 21.14.4,     it escapes backslashes, dollar signs, and backticks only when BASH_VERSION is set, so zsh receives the raw     value. The script assigns that value to PS1. In zsh with PROMPT_SUBST, an attacker-influenced environment     directory, --prompt, or VIRTUALENV_PROMPT value containing command, parameter, or arithmetic expansion     syntax can therefore execute commands in the user's shell each time the prompt is drawn. A percent sign is     separately interpreted as a zsh prompt escape but does not by itself execute commands. Plain zsh with     PROMPT_SUBST disabled and bash are not affected by this mechanism. This issue is fixed in version 21.14.4.
    (CVE-2026-113726)

  - 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. (CVE-2026-113732)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-3409 advisory.

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, the stdlib venv     creator reads generated pyvenv.cfg with str.splitlines() and merges parsed keys over virtualenv's selected     configuration. An untrusted caller who influences the destination pathname can include a line-boundary     character such as U+2028 to inject keys including home and include-system-site-packages, causing path data     to change configuration structure before final output. Setting include-system-site-packages to true     weakens environment isolation, while an altered home can change which standard-library files the     interpreter loads if the attacker also controls that location. The builtin creator does not use this     readback path. This issue is fixed in version 21.14.9. (CVE-2026-113715)

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, virtualenv's     ScriptMakerCustom and pip pass an incompletely quoted interpreter path to distlib ScriptMaker when     generating POSIX console scripts. When the path contains a space or produces a shebang longer than 127     bytes, distlib emits a /bin/sh wrapper whose double-quoted interpreter path still expands command     substitutions and backticks. An attacker who influences the environment destination can therefore execute     commands with the user's privileges when the user later runs a generated launcher; environment creation     and activation do not trigger the command. Existing launchers are not repaired by upgrading virtualenv     alone and must be regenerated, while a later independent pip installation or upgrade can reintroduce an     affected launcher because pip's vendored distlib is unchanged. The virtualenv fix is released in version     21.14.9. (CVE-2026-113722)

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, caller-supplied     prompt text can become executable syntax in the bash activation prompt. An attacker must influence the     value passed to virtualenv, and a user must subsequently activate the environment and draw the prompt.
    This vulnerability is fixed in 21.14.9. (CVE-2026-113723)

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.7, the bash     activate script escapes the environment name for only one of the two passes bash makes over PS1, so a     backslash in the name undoes the escaping and a name containing \$(...) runs as commands in the user's     shell each time bash draws the prompt. This issue is fixed in version 21.14.7. (CVE-2026-113725)

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.13.0, the bash     activate script that zsh also sources leaves the environment name unescaped; from 21.13.0 until 21.14.4,     it escapes backslashes, dollar signs, and backticks only when BASH_VERSION is set, so zsh receives the raw     value. The script assigns that value to PS1. In zsh with PROMPT_SUBST, an attacker-influenced environment     directory, --prompt, or VIRTUALENV_PROMPT value containing command, parameter, or arithmetic expansion     syntax can therefore execute commands in the user's shell each time the prompt is drawn. A percent sign is     separately interpreted as a zsh prompt escape but does not by itself execute commands. Plain zsh with     PROMPT_SUBST disabled and bash are not affected by this mechanism. This issue is fixed in version 21.14.4.
    (CVE-2026-113726)

    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. (CVE-2026-113732)

    virtualenv is a tool for creating isolated virtual python environments. From 20.26.6 until 21.14.2,     ViaTemplateActivator.instantiate_template() replaces placeholders one key at a time across the complete     activation template, so trigger names such as __VIRTUAL_NAME__, __VIRTUAL_ENV__, or __VIRTUAL_PROMPT__     inside an already substituted and quoted environment path or prompt can be replaced during a later pass.
    The later value's quoting can close the earlier literal and execute the remaining path when a user     activates the environment through bash, fish, xonsh, or activate_this.py. The distinct csh prompt-display     token __VIRTUAL_PROMPT_DISPLAY_TCSH__ can instead break the generated script without establishing command     execution. The attacker must influence the destination path or --prompt, and a value without a relevant     placeholder name does not trigger this mechanism. This issue is fixed in version 21.14.2.
    (CVE-2026-113776)

    virtualenv is a tool for creating isolated virtual python environments. From 21.14.9 until 21.14.13, the     bash bin/activate script can copy an attacker-controlled --prompt value into PS1 without escaping dollar     signs or backticks when both promptvars and POSIX mode are disabled during activation. Re-enabling     promptvars, running set -o posix, or starting an interactive child bash that inherits the exported PS1 can     then expand command substitution in the stored VIRTUAL_ENV_PROMPT value and execute commands as the user     who activates the environment. This issue is fixed in version 21.14.13. (CVE-2026-115586)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-3410 advisory.

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, the stdlib venv     creator reads generated pyvenv.cfg with str.splitlines() and merges parsed keys over virtualenv's selected     configuration. An untrusted caller who influences the destination pathname can include a line-boundary     character such as U+2028 to inject keys including home and include-system-site-packages, causing path data     to change configuration structure before final output. Setting include-system-site-packages to true     weakens environment isolation, while an altered home can change which standard-library files the     interpreter loads if the attacker also controls that location. The builtin creator does not use this     readback path. This issue is fixed in version 21.14.9. (CVE-2026-113715)

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, virtualenv's     ScriptMakerCustom and pip pass an incompletely quoted interpreter path to distlib ScriptMaker when     generating POSIX console scripts. When the path contains a space or produces a shebang longer than 127     bytes, distlib emits a /bin/sh wrapper whose double-quoted interpreter path still expands command     substitutions and backticks. An attacker who influences the environment destination can therefore execute     commands with the user's privileges when the user later runs a generated launcher; environment creation     and activation do not trigger the command. Existing launchers are not repaired by upgrading virtualenv     alone and must be regenerated, while a later independent pip installation or upgrade can reintroduce an     affected launcher because pip's vendored distlib is unchanged. The virtualenv fix is released in version     21.14.9. (CVE-2026-113722)

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, caller-supplied     prompt text can become executable syntax in the bash activation prompt. An attacker must influence the     value passed to virtualenv, and a user must subsequently activate the environment and draw the prompt.
    This vulnerability is fixed in 21.14.9. (CVE-2026-113723)

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.7, the bash     activate script escapes the environment name for only one of the two passes bash makes over PS1, so a     backslash in the name undoes the escaping and a name containing \$(...) runs as commands in the user's     shell each time bash draws the prompt. This issue is fixed in version 21.14.7. (CVE-2026-113725)

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.13.0, the bash     activate script that zsh also sources leaves the environment name unescaped; from 21.13.0 until 21.14.4,     it escapes backslashes, dollar signs, and backticks only when BASH_VERSION is set, so zsh receives the raw     value. The script assigns that value to PS1. In zsh with PROMPT_SUBST, an attacker-influenced environment     directory, --prompt, or VIRTUALENV_PROMPT value containing command, parameter, or arithmetic expansion     syntax can therefore execute commands in the user's shell each time the prompt is drawn. A percent sign is     separately interpreted as a zsh prompt escape but does not by itself execute commands. Plain zsh with     PROMPT_SUBST disabled and bash are not affected by this mechanism. This issue is fixed in version 21.14.4.
    (CVE-2026-113726)

    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. (CVE-2026-113732)

    virtualenv is a tool for creating isolated virtual python environments. From 20.26.6 until 21.14.2,     ViaTemplateActivator.instantiate_template() replaces placeholders one key at a time across the complete     activation template, so trigger names such as __VIRTUAL_NAME__, __VIRTUAL_ENV__, or __VIRTUAL_PROMPT__     inside an already substituted and quoted environment path or prompt can be replaced during a later pass.
    The later value's quoting can close the earlier literal and execute the remaining path when a user     activates the environment through bash, fish, xonsh, or activate_this.py. The distinct csh prompt-display     token __VIRTUAL_PROMPT_DISPLAY_TCSH__ can instead break the generated script without establishing command     execution. The attacker must influence the destination path or --prompt, and a value without a relevant     placeholder name does not trigger this mechanism. This issue is fixed in version 21.14.2.
    (CVE-2026-113776)

    virtualenv is a tool for creating isolated virtual python environments. From 21.14.9 until 21.14.13, the     bash bin/activate script can copy an attacker-controlled --prompt value into PS1 without escaping dollar     signs or backticks when both promptvars and POSIX mode are disabled during activation. Re-enabling     promptvars, running set -o posix, or starting an interactive child bash that inherits the exported PS1 can     then expand command substitution in the stored VIRTUAL_ENV_PROMPT value and execute commands as the user     who activates the environment. This issue is fixed in version 21.14.13. (CVE-2026-115586)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2026-113732)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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. (CVE-2026-113732)

ID	Name	Product	Family	Type	Severity
377996	CentOS Linux 7 [TuxCare] Security Update: python-virtualenv Multiple Vulnerabilities (CENTOS7:CLSA-2026:1793888087)	Nessus	CentOS Local Security Checks	Local	high
377956	Amazon Linux 2023 : python3-virtualenv (ALAS2023-2026-3409)	Nessus	Amazon Linux Local Security Checks	Local	high
377898	Amazon Linux 2023 : python3.13-virtualenv (ALAS2023-2026-3410)	Nessus	Amazon Linux Local Security Checks	Local	high
370939	Linux Distros Unpatched Vulnerability : CVE-2026-113732	Nessus	Misc.	Local	high
476643	Chainguard: openstack-rally-2025.2: security update to 4.1.0-r4	Tenable Cloud Security	Chainguard Local Security Checks	Local	high
476643	Chainguard: openstack-rally-2025.2: security update to 4.1.0-r4	Tenable Self-Hosted Container Security	Chainguard Local Security Checks	Local	high
476570	SCA: security update for virtualenv (GHSA-c947-3pg5-gm8q)	Tenable Cloud Security	SCA Checks	Local	high
476570	SCA: security update for virtualenv (GHSA-c947-3pg5-gm8q)	Tenable Self-Hosted Container Security	SCA Checks	Local	high

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