{"id":"CVE-2026-102938","summary":"virtualenv writes prompt values into pyvenv.cfg without sanitizing line boundaries, allowing configuration injection","details":"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.","aliases":["GHSA-9h9j-4vrj-gf7g","PYSEC-2026-4012"],"modified":"2026-10-01T03:47:45.527743496Z","published":"2026-09-29T20:58:20.696Z","database_specific":{"cwe_ids":["CWE-93"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102938.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/pypa/virtualenv/releases/tag/21.7.11"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102938.json"},{"type":"ADVISORY","url":"https://github.com/pypa/virtualenv/security/advisories/GHSA-9h9j-4vrj-gf7g"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-102938"},{"type":"FIX","url":"https://github.com/pypa/virtualenv/commit/a30f995461043acb6cacbf3a890951563ccf7140"},{"type":"FIX","url":"https://github.com/pypa/virtualenv/pull/3247"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/pypa/virtualenv","events":[{"introduced":"0"},{"fixed":"a30f995461043acb6cacbf3a890951563ccf7140"},{"fixed":"73e352ae02bfa52ffc0e307b04f1b6a7168c4eb0"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"21.7.11"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["21.7.10","21.7.9","21.7.8","21.7.7","21.7.6","21.7.5","21.7.4","21.7.3","21.7.2","21.7.1","21.7.0","21.6.1","21.6.0","21.5.2","21.5.1","21.5.0","21.4.3","21.4.2","21.4.1","21.4.0","21.3.3","21.3.2","21.3.1","21.3.0","21.2.4","21.2.3","21.2.2","21.2.1","21.2.0","21.1.0","21.0.0","20.39.1","20.39.0","20.38.0","20.37.0","20.27.3","20.27.2","20.24.3","20.3.0","20.0.32","20.0.7","20.0.0b2","20.0.0b1"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-102938.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N"}]}