CVE-2026-102938

Name	CVE-2026-102938
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1149650

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
python-virtualenv (PTS)	bookworm	20.17.1+ds-1	vulnerable
	trixie	20.31.2+ds-1+deb13u1	vulnerable
	forky, sid	21.5.1+ds-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
python-virtualenv	source	(unstable)	(unfixed)			1149650

Notes

[trixie] - python-virtualenv <no-dsa> (Minor issue)
[bookworm] - python-virtualenv <postponed> (Minor issue)
https://github.com/pypa/virtualenv/security/advisories/GHSA-9h9j-4vrj-gf7g
https://github.com/pypa/virtualenv/pull/3247
Fixed by: https://github.com/pypa/virtualenv/commit/a30f995461043acb6cacbf3a890951563ccf7140 (21.7.11)