CVE-2026-102938

virtualenv writes prompt values into pyvenv.cfg without sanitizing line boundaries, allowing configuration injection

State
Published
Severity
5.8 Medium
Published
Sep 29, 2026
Updated
Sep 30, 2026
Reserved
Sep 29, 2026

Read the record on cve.org

Description

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.7.11, PyEnvCfg.write() writes prompt values verbatim to the line-oriented pyvenv.cfg format while PyEnvCfg._read_values() parses the file with str.splitlines() and accepts the last value for duplicate keys. An attacker who influences --prompt, VIRTUALENV_PROMPT, or configuration input can insert a recognized line boundary and additional keys, including home, causing consumers to use an attacker-selected base interpreter or corrupted environment metadata. The security impact requires prompt input from outside the operator's trust boundary; directly supplied prompt content primarily corrupts the operator's own environment. This issue is fixed in version 21.7.11.

Scores

CVSSScoreVectorSource
4.05.8 MediumCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:L/VI:H/VA:L/SC:N/SI:N/SA:NGitHub_M

Weaknesses

  • CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')

Affected Products

ProductVersions
virtualenvpypa
  • < 21.7.11Affected

References

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