The vulnerability lies in mise’s HTTP backend, which builds the symlink destination for installed tools using the raw resolved version string for non‑latest releases. Because this raw value can be an absolute path, the backend may create symlinks outside the intended installation tree. The flaw enables an attacker to place executable symlinks in arbitrary locations if they control a repository’s .tool-versions file or the bin_path configuration. The weakness is a classic path traversal (CWE‑22) that can lead to unauthorized file system modifications or unintended code execution by spoiling environment paths. The CVSS score of 5.5 reflects moderate risk for local systems.

All installations of the jdx open-source tool manager 'mise', specifically any deployment running a version earlier than 2026.6.1. The issue impacts versions that use the HTTP backend for tool installation. Users of the latest release (2026.6.1 or later) are no longer affected.

The CVSS score of 5.5 indicates a medium severity vulnerability when it comes to privilege level and affected scope. No EPSS score is available, so the exploitation probability is unknown at this time, and it is not listed in the CISA KEV catalog. The likely attack vector would require local compromise or control over a repository from which mise downloads the .tool-versions file; from there, an attacker could craft absolute path strings that force symlink creation outside the installation directory. The resulting arbitrary symlink could point to an attacker‑controlled executable that would run when added to the user’s PATH, enabling privilege escalation or malicious code execution.