This vulnerability arises from improper link resolution before file access in kitty's drag source staging path. Specifically, the function subdir_data_for_drag() in kitty/dnd.c constructs a path string and opens it with safe_open() instead of walking the directory tree component by component. An attacker can declare two entries with the same name: the first a symlink pointing to an arbitrary absolute path and the second a directory. The code ignores mkdirat() failure with EEXIST, causing subsequent path resolution to follow the symlink outside the staging directory. This directory descriptor is then used for creating files and directories, allowing creation at any path writable by the user running kitty. Entry names are sanitized, but symlink targets are not validated. Files are created with O_CREAT | O_WRONLY | O_EXCL and mode 0644, preventing overwriting existing files, and directories with mode 0755, allowing creation of intermediate directories.

An attacker with the ability to write to the terminal can create files and directories at arbitrary paths writable by the user running kitty, outside the intended staging directory. This could lead to unauthorized file creation, potentially impacting user data or environment. However, existing files cannot be overwritten, and no privilege escalation or remote exploitation is indicated. The attack requires local access and user interaction.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should avoid running vulnerable versions (>=0.47.0 <0.49.0) or restrict access to trusted users only. Monitoring for updates from the vendor is recommended.