CVE-2026-113717 is a vulnerability in virtualenv's pip seeder when used with the --download option. The issue arises because the pip seeder downloads wheels without performing virtualenv's wheel digest verification, allowing an attacker-controlled index to serve a modified pip wheel that bypasses integrity checks. This can lead to installation of tampered pip code in the created environment. Both --seeder pip and --download options must be enabled for exploitation. The vulnerability was reported by Anthropic's OSS Scanner and fixed in virtualenv version 4.7.0_1.