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Fencer Vulns
high 7.8

CVE-2026-113726 json

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

published 2026-10-20 19 d ago modified 2026-10-29 10 d ago also BIT-virtualenv-2026-113726 , EUVD-2026-106869 , GHSA-5vjq-rrrf-7h2q

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 28%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi virtualenv 21.14.4
  • bitnami virtualenv 21.14.4
  • virtualenv virtualenv 21.14.4
  • python-virtualenv openSUSE Tumbleweed 21.15.1-1.1

opensuse advisories openSUSE-SU-2026:12372-1

  • python-virtualenv Azure Linux 3.0 20.36.1-10

azure linux advisories AZL-110100

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-113726 updated cvss 7.8

virtualenv: virtualenv: Arbitrary command execution via unescaped prompt variables in zsh

  • Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-service-api-rhel9
    affected: no fix planned “Will not fix”
  • Red Hat Ansible Automation Platform 2 python-virtualenv 20.25.1-2.el10ap, python3.12-virtualenv 20.25.1-2.el9ap, ansible-automation-platform-26/controller-rhel9, ansible-automation-platform-27/controller-rhel9, ansible-automation-platform-26/lightspeed-chatbot-rhel9 Red Hat OpenShift AI (RHOAI) rhoai/odh-ta-lmes-job-rhel9, rhoai/odh-feature-server-rhel9, rhai-early-access/docling-serve-cuda-rhel9, rhoai/odh-kserve-storage-initializer-rhel9, rhoai/odh-training-rocm64-torch28-py312-rhel9, rhoai/odh-trustyai-nemo-guardrails-server-rhel9, +3 more Red Hat OpenShift Dev Spaces devspaces/udi-rhel9 Red Hat Satellite 6 satellite/iop-yuptoo-rhel9, satellite/iop-host-inventory-rhel9, satellite/iop-advisor-backend-rhel9
    affected: no fix available
  • Red Hat Ansible Automation Platform 2 python3.11-virtualenv 20.25.1-1.el9ap, ansible-automation-platform-26/eda-controller-rhel9, ansible-automation-platform-27/eda-controller-rhel9
    not affected: vulnerable code not present
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-kserve-agent-rhel9, rhoai/odh-kserve-router-rhel9, rhoai/odh-kserve-controller-rhel9 Red Hat OpenShift Container Platform 4 python-virtualenv 20.25.1-2.el10ap
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
12 d ago

Exploit prediction

0.34% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
GitHub 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
OSV 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
pypi virtualenv
<21.14.4
21.14.4
bitnami virtualenv
<21.14.4
21.14.4

Affected products

  • pypa virtualenv

Classification

Weakness
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command
  • CWE-116 Improper Encoding or Escaping of Output

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.