virtualenv activation scripts run code from a path that contains a placeholder name (pypa virtualenv)

CVE-2026-113776
HIGH 7.8

At a glance

Source
NVD
EPSS
EPSS 0.27 % · percentile 19 ()
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Awaiting Analysis

Description

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.

Weaknesses (CWE)

  • CWE-78 — Improper Neutralization of Special Elements used in an OS Command
  • CWE-94 — Improper Control of Generation of Code

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HGitHub_M
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HNVD · security-advisories@github.com (Secondary)

Advisories

European references

Affected products

ProductVersions
pypa · virtualenvaffected >= 20.26.6, < 21.14.2

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD