Skip to content
Fencer Intel
medium 4.5

CVE-2026-113721 json

virtualenv: Generated files can follow existing destination links

published 20d ago modified 11d ago also BIT-virtualenv-2026-113721 , EUVD-2026-105303 , GHSA-558c-9hv2-4prj

cvss
4.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits
0
none known

Summary

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, ViaTemplateActivator._generate() removes an existing output only when Path.exists() is true, allowing a dangling symlink to survive and redirect generated activation content, while PyEnvCfg.write() opens pyvenv.cfg without first replacing an existing symbolic or hard link. Another local account that prepares final entries inside the destination can therefore cause environment creation to create or overwrite files outside the requested tree with constrained virtualenv-generated content and the invoking user's permissions. The destination parent must remain controlled by the environment owner during creation; concurrent parent-directory replacement is a separate concern. This issue is fixed in version 21.14.9.

Patch / fix

  • pypi virtualenv 21.14.9
  • bitnami virtualenv 21.14.9
  • virtualenv virtualenv 21.14.9
  • python-virtualenv Azure Linux 3.0 20.36.1-10

azure linux advisories AZL-110124

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

Is CVE-2026-113721 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

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-2026-113721 updated cvss 4.5

virtualenv: virtualenv: Arbitrary file overwrite via insecure symlink handling

  • Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-service-api-rhel9 Red Hat Ansible Automation Platform 2 python-virtualenv 20.25.1-2.el10ap, python3.11-virtualenv 20.25.1-1.el9ap, python3.12-virtualenv 20.25.1-2.el9ap, ansible-automation-platform-26/controller-rhel9, ansible-automation-platform-27/controller-rhel9, ansible-automation-platform-26/eda-controller-rhel9, +2 more Red Hat OpenShift AI (RHOAI) rhoai/odh-ta-lmes-job-rhel9, rhoai/odh-kserve-agent-rhel9, rhoai/odh-kserve-router-rhel9, rhoai/odh-feature-server-rhel9, rhoai/odh-kserve-controller-rhel9, rhai-early-access/docling-serve-cuda-rhel9, +6 more Red Hat OpenShift Container Platform 4 python-virtualenv 20.25.1-2.el10ap 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 “Fix deferred”

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
partial
Assessed
12d ago

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 4.5 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
GitHub 3.1 4.5 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
OSV 3.1 4.5 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L

Affected packages

ecosystem package affected fixed in
pypi virtualenv
<21.14.9
21.14.9
bitnami virtualenv
<21.14.9
21.14.9

Affected products

  • pypa virtualenv

Classification

Weakness
  • CWE-59 Improper Link Resolution Before File Access

References

Sources

Fencer Intel 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.