CVE-2026-102938 — virtualenv writes prompt values into pyvenv.cfg without sanitizing line boundaries, allowing configuration injection
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 w…
Published: 2026-09-29 · CVSS: 5.8 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7