CVE-2026-113718

virtualenv: Xonsh activation literals depend on the script decoding codec

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, POSIX xonsh activation quote() uses repr() to write printable non-ASCII prompt or destination data into UTF-8 activate.xsh, while xonsh can read that script using $XONSH_ENCODING. Under a legacy multibyte codec such as GBK or Big5, a UTF-8 trail byte can consume the backslash before an adjacent quote, allowing the literal to close and attacker-influenced statements to execute when the user sources the generated script. This issue is fixed in version 21.14.9.

Affected

pypa · virtualenv

CVSS v4.0 GITHUB

7.1 HIGHCVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v4.0 GitHub

7.1 HIGHCVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

EPSS

0.24% chance of exploitation in the next 30 days, 15th percentile

Published

2026-10-20

Updated

2026-10-27

Proof-of-concept exploits (1)

• advisories/GHSA-394h-qwmc-48pffind archive

CVE references

• pypa/virtualenv/commit/e5fc2e6e189a877ff559af288919e3525d13e5e0REFERENCE
• pypa/virtualenv/pull/3432REFERENCE
• pypa/virtualenv/releases/tag/21.14.9REFERENCE
• pypa/virtualenv/security/advisories/GHSA-394h-qwmc-48pfREFERENCE

References

• CVE Record
• NVD entry