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High ALAS2-2026-4085 4 CVEs

Important: python-virtualenv security update (Amazon Linux 2)

Published Nov 9, 2026 · Updated Nov 9, 2026

Summary

Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: CVE-2026-115586: 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-2026-113726: 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-2026-113725: 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-2026-113723: 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.

Fixed packages 1

ReleasePackageFixed in
Amazon Linux · 2 python-virtualenv 0:15.1.0-4.amzn2.0.1

Vulnerabilities 4

  • High 7.8

    virtualenv bash activate runs commands from an environment name with a backslash before $

    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 conta…

  • High 7.8

    virtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST

    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 onl…

  • High 7.1

    virtualenv: Bash prompt values can change meaning under older compatibility modes

    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 subseq…

  • High 7.1

    virtualenv: Bash activator leaves the --prompt value unescaped in PS1 when promptvars is off, so prompt expansion later executes it (regression in 21.14.9)

    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…

References

  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-113723.html
  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-113725.html
  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-113726.html
  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-115586.html