Vulnerabilities in pkg:pypi/virtualenv

PACKAGE
Advisory Identifier: GHSA-p58f-9548-mpm2
Advisory Summary

CVE-2026-102925 is a HIGH (CVSS 7.8) virtualenv bash and fish activation vulnerability (CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')) affecting Virtualenv libraries in the PyPI ecosystem. The issue involves virtualenv bash and fish activation scripts execute commands embedded in paths. Remediation is available by upgrading affected packages to version 21.7.13.

7 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:pypi/virtualenv

7 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:pypi/virtualenv. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-p58f-9548-mpm2 CVE-2026-102925 HIGH virtualenv bash and fish activation scripts execute commands embedded in paths
GHSA-x78j-v8h9-3j2q CVE-2026-102937 HIGH virtualenv: Command injection via --prompt in activate.bat (batch activator)
GHSA-94p9-xgh2-xp45 CVE-2026-102930 HIGH virtualenv: Downloaded seed wheels (pip/setuptools) are not integrity-checked before use
GHSA-9h9j-4vrj-gf7g CVE-2026-102938 MODERATE virtualenv writes prompt values into pyvenv.cfg without sanitizing line boundaries, allowing configuration injection
GHSA-597g-3phw-6986 CVE-2026-22702 MODERATE virtualenv Has TOCTOU Vulnerabilities in Directory Creation
GHSA-rqc4-2hc7-8c8v CVE-2024-53899 HIGH virtualenv allows command injection through activation scripts for a virtual environment
GHSA-3jhc-wjqf-5f2c CVE-2011-4617 MODERATE Virtualenv Allows Symlink Attack on /tmp/

CVE-2026-102925 at a Glance

CVE Identifier CVE-2026-102925
GHSA Identifier GHSA-p58f-9548-mpm2
Severity HIGH
CVSS v3.1 Base Score 7.8
CWE Classification CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Affected Product Virtualenv
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-102925

To remediate this vulnerability, upgrade all affected Virtualenv dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

virtualenv fixed: 21.7.13
pip install virtualenv>=21.7.13
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show virtualenv

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-102925, inspect your installed packages using pip:

pip show virtualenv

Analyze the terminal output to locate any version of Virtualenv in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 21.7.13), your application is affected.

Note: The pip show virtualenv command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'), where the product constructs all or part of an os command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended os command when it is sent to a downstream component. In Virtualenv, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact The generated `activate` (bash/zsh) and `activate.fish` scripts interpolate a `shlex.quote`-ed value into a position that quotes it a second time. The extra quotes terminate the quoted run early and leave part of the value parsed as shell code, so a path containing shell metacharacters runs commands when a user sources the activation script. `activate` is affected through the virtual environment's own path, on the branch that reports a relocated environment: ```sh echo "Virtual environment directory __VIRTUAL_ENV__ does not exist!" >&2 ``` For a destination named `x'$(id)'y`, `shlex.quote` emits `'x'"'"'$(id)'"'"'y'`. The inner `"` closes the enclosing double quote and `$(id)` is left unquoted. Backtick and `;` payloads reach the same result. This branch runs whenever the recorded path is absent, which is the normal case for a virtual environment copied or distributed to another machine. `activate.fish` is affected through the interpreter's Tcl/Tk library paths: ```fish set -gx TCL_LIBRARY '__TCL_LIBRARY__' ``` `shlex.quote` already returns `'/tcl/(cmd)/lib'`, so the rendered line is `''/tcl/(cmd)/lib''`. fish concatenates the adjacent quoted runs and expands the `(cmd)` left between them. The same doubling also splits a path containing a space into two list elements, corrupting `TCL_LIBRARY` and `TK_LIBRARY`. This is the same defect class as GHSA-x78j-v8h9-3j2q, which covered `activate.bat`. ### Patches Fixed in 21.7.13 by moving the placeholders outside the surrounding quotes, so each value keeps only the quoting `shlex.quote` applied. Fix: https://github.com/pypa/virtualenv/pull/3252 ### Workarounds Avoid creating or distributing virtual environments whose path contains `'`, `` ` ``, `$`, `;`, `(` or `)`, and inspect the generated activation script before sourcing one you did not create.

CVE-2026-102925 Affected Virtualenv Versions

1 component(s)
Fixed Versions:
21.7.13
Product / Package Ecosystem Affected Versions Fixed Version
virtualenv
PyPI
< 21.7.13
21.7.13

References

Frequently Asked Questions

What is CVE-2026-102925?
CVE-2026-102925 is a security vulnerability in Virtualenv involving virtualenv bash and fish activation scripts execute commands embedded in paths under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection').
Which Virtualenv versions are affected?
Affected versions include releases prior to 21.7.13 across affected packages: virtualenv.
What version fixes CVE-2026-102925?
Upgrading to 21.7.13 (or the latest patched release for your respective branch) resolves the vulnerability.
Is virtualenv affected?
Yes, virtualenv is affected in releases prior to 21.7.13. Upgrade your dependency to 21.7.13 or later.
What is the CVSS score of CVE-2026-102925?
CVE-2026-102925 has a CVSS v3.1 base score of 7.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-102925?
CVE-2026-102925 is classified under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') (The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.).
How can I check PyPI dependencies for CVE-2026-102925?
Run the dependency tree command: 'pip show virtualenv'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-p58f-9548-mpm2",
  "modified" : "2026-10-01T15:09:18Z",
  "published" : "2026-10-01T15:09:17Z",
  "aliases" : [ "CVE-2026-102925" ],
  "summary" : "virtualenv bash and fish activation scripts execute commands embedded in paths",
  "details" : "### Impact\n\nThe generated `activate` (bash/zsh) and `activate.fish` scripts interpolate a `shlex.quote`-ed value into a position that quotes it a second time. The extra quotes terminate the quoted run early and leave part of the value parsed as shell code, so a path containing shell metacharacters runs commands when a user sources the activation script.\n\n`activate` is affected through the virtual environment's own path, on the branch that reports a relocated environment:\n\n```sh\necho \"Virtual environment directory __VIRTUAL_ENV__ does not exist!\" >&2\n```\n\nFor a destination named `x'$(id)'y`, `shlex.quote` emits `'x'\"'\"'$(id)'\"'\"'y'`. The inner `\"` closes the enclosing double quote and `$(id)` is left unquoted. Backtick and `;` payloads reach the same result. This branch runs whenever the recorded path is absent, which is the normal case for a virtual environment copied or distributed to another machine.\n\n`activate.fish` is affected through the interpreter's Tcl/Tk library paths:\n\n```fish\nset -gx TCL_LIBRARY '__TCL_LIBRARY__'\n```\n\n`shlex.quote` already returns `'/tcl/(cmd)/lib'`, so the rendered line is `''/tcl/(cmd)/lib''`. fish concatenates the adjacent quoted runs and expands the `(cmd)` left between them. The same doubling also splits a path containing a space into two list elements, corrupting `TCL_LIBRARY` and `TK_LIBRARY`.\n\nThis is the same defect class as GHSA-x78j-v8h9-3j2q, which covered `activate.bat`.\n\n### Patches\n\nFixed in 21.7.13 by moving the placeholders outside the surrounding quotes, so each value keeps only the quoting `shlex.quote` applied. Fix: https://github.com/pypa/virtualenv/pull/3252\n\n### Workarounds\n\nAvoid creating or distributing virtual environments whose path contains `'`, `` ` ``, `$`, `;`, `(` or `)`, and inspect the generated activation script before sourcing one you did not create.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "virtualenv"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "21.7.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 21.7.12"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/pypa/virtualenv/security/advisories/GHSA-p58f-9548-mpm2"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-102925"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/virtualenv/pull/3252"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/virtualenv/commit/4d5a105ec2a2723b8c7f4571bb68f4f71d01e3f6"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/virtualenv/PYSEC-2026-4013.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/pypa/virtualenv"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/virtualenv/releases/tag/21.7.13"
  }, {
    "type" : "WEB",
    "url" : "https://pypi.org/project/virtualenv"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-78" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-01T15:09:17Z",
    "nvd_published_at" : "2026-09-29T21:17:18Z"
  }
}