{"id":"PYSEC-2026-4014","summary":"Command injection via --prompt in activate.bat (batch activator)","details":"`BatchActivator.quote()` returned its input unchanged, the only activator with\nno escaping at all. `--prompt`, the `VIRTUALENV_PROMPT` environment variable,\nand the config file all set the prompt, and `activate.bat` writes it straight\ninto `@set \"VAR=value\"`. A prompt containing a double quote closes that string\nearly, and whatever follows runs as live cmd.exe syntax. For example, a venv\ncreated with `--prompt 'x\" & calc & \"'` runs `calc` the moment someone runs\n`activate.bat`.\n\nAnyone who templates a prompt from untrusted input (a CI job using a branch\nname, a wrapper script deriving an environment name from user input) hands an\nattacker code execution in the shell of anyone who activates the resulting venv\non Windows.\n\nFixed in 21.7.12 by escaping the characters cmd.exe treats as live syntax\ninside this construct.\n","aliases":["CVE-2026-102937","GHSA-x78j-v8h9-3j2q"],"modified":"2026-09-30T16:45:02.570148666Z","published":"2026-09-18T01:41:45Z","references":[{"type":"WEB","url":"https://github.com/pypa/virtualenv/security/advisories/GHSA-x78j-v8h9-3j2q"},{"type":"WEB","url":"https://github.com/pypa/virtualenv/pull/3250"},{"type":"FIX","url":"https://github.com/pypa/virtualenv/commit/d721ff140ce4afdc2a9b76751e4584e25d9fbea6"},{"type":"WEB","url":"https://github.com/pypa/virtualenv/releases/tag/21.7.12"},{"type":"PACKAGE","url":"https://github.com/pypa/virtualenv"},{"type":"PACKAGE","url":"https://pypi.org/project/virtualenv"}],"affected":[{"package":{"name":"virtualenv","ecosystem":"PyPI","purl":"pkg:pypi/virtualenv"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"21.7.12"}]}],"versions":["0.8","0.8.1","0.8.2","0.8.3","0.8.4","0.9","0.9.1","0.9.2","1.0","1.1","1.10","1.10.1","1.11","1.11.1","1.11.2","1.11.3","1.11.4","1.11.5","1.11.6","1.2","1.3","1.3.1","1.3.2","1.3.3","1.3.4","1.4","1.4.1","1.4.2","1.4.3","1.4.4","1.4.5","1.4.6","1.4.7","1.4.8","1.4.9","1.4rc1","1.5","1.5.1","1.5.2","1.6","1.6.1","1.6.2","1.6.3","1.6.4","1.7","1.7.1","1.7.1.1","1.7.1.2","1.7.2","1.8","1.8.1","1.8.2","1.8.3","1.8.4","1.9","1.9.1","12.0","12.0.1","12.0.2","12.0.4","12.0.5","12.0.6","12.0.7","12.1.0","12.1.1","13.0.0","13.0.1","13.0.2","13.0.3","13.1.0","13.1.1","13.1.2","14.0.0","14.0.1","14.0.2","14.0.3","14.0.4","14.0.5","14.0.6","15.0.0","15.0.1","15.0.2","15.0.3","15.1.0","15.2.0","16.0.0","16.1.0","16.2.0","16.3.0","16.3.1.dev0","16.4.0","16.4.1","16.4.3","16.4.4.dev0","16.5.0","16.6.0","16.6.1","16.6.2","16.7.0","16.7.1","16.7.10","16.7.11","16.7.12","16.7.2","16.7.3","16.7.4","16.7.5","16.7.6","16.7.7","16.7.8","16.7.9","20.0.0","20.0.0b1","20.0.0b2","20.0.1","20.0.10","20.0.11","20.0.12","20.0.13","20.0.14","20.0.15","20.0.16","20.0.17","20.0.18","20.0.19","20.0.2","20.0.20","20.0.21","20.0.22","20.0.23","20.0.24","20.0.25","20.0.26","20.0.27","20.0.28","20.0.29","20.0.3","20.0.30","20.0.31","20.0.32","20.0.33","20.0.34","20.0.35","20.0.4","20.0.5","20.0.6","20.0.7","20.0.8","20.0.9","20.1.0","20.10.0","20.11.0","20.11.1","20.11.2","20.12.0","20.12.1","20.13.0","20.13.1","20.13.2","20.13.3","20.13.4","20.14.0","20.14.1","20.15.0","20.15.1","20.16.0","20.16.1","20.16.2","20.16.3","20.16.4","20.16.5","20.16.6","20.16.7","20.17.0","20.17.1","20.18.0","20.19.0","20.2.0","20.2.1","20.2.2","20.20.0","20.21.0","20.21.1","20.22.0","20.23.0","20.23.1","20.24.0","20.24.1","20.24.2","20.24.3","20.24.4","20.24.5","20.24.6","20.24.7","20.25.0","20.25.1","20.25.2","20.25.3","20.26.0","20.26.1","20.26.2","20.26.3","20.26.4","20.26.5","20.26.6","20.27.0","20.27.1","20.28.0","20.28.1","20.29.0","20.29.1","20.29.2","20.29.3","20.3.0","20.3.1","20.30.0","20.31.0","20.31.1","20.31.2","20.32.0","20.33.0","20.33.1","20.34.0","20.35.0","20.35.1","20.35.2","20.35.3","20.35.4","20.36.0","20.36.1","20.38.0","20.39.0","20.39.1","20.4.0","20.4.1","20.4.2","20.4.3","20.4.4","20.4.5","20.4.6","20.4.7","20.5.0","20.6.0","20.7.0","20.7.1","20.7.2","20.8.0","20.8.1","20.9.0","21.0.0","21.1.0","21.2.0","21.2.1","21.2.2","21.2.3","21.2.4","21.3.0","21.3.1","21.3.2","21.3.3","21.4.0","21.4.1","21.4.2","21.4.3","21.5.0","21.5.1","21.5.2","21.6.0","21.6.1","21.7.0","21.7.1","21.7.10","21.7.11","21.7.2","21.7.3","21.7.4","21.7.5","21.7.6","21.7.7","21.7.8","21.7.9"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/virtualenv/PYSEC-2026-4014.yaml"}}],"schema_version":"1.9.0","credits":[{"name":"Bernát Gábor","type":"FINDER"}]}