CVE-2026-102938

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.

• https://github.com/pypa/virtualenv/commit/a30f995461043acb6cacbf3a890951563ccf7140
• https://github.com/pypa/virtualenv/pull/3247
• https://github.com/pypa/virtualenv/releases/tag/21.7.11
• https://github.com/pypa/virtualenv/security/advisories/GHSA-9h9j-4vrj-gf7g