`path` and `filename` are free-form strings that can come from a
workflow's JSON, not just a person typing into the local UI. Only the
final path segment was ever sanitized (make_pathname/sanitize_filename),
so a value like `../../../etc` or an absolute path could make
ImageSaver.save_images() create directories and write the image/JSON
sidecar outside ComfyUI's output directory (CWE-22/CWE-73). This is
what caused v1.24.0 to be banned on the Comfy Registry
(Comfy-Org/registry-backend#206).
Add utils.resolve_within_output(), which joins path pieces onto
folder_paths.output_directory, resolves symlinks, and rejects the
result if it escapes that directory. Apply it everywhere
ImageSaver.save_images() turns `path`/`filename` into a filesystem
path: the output directory itself, the final image target, and the
optional workflow-JSON sidecar. Nested relative subfolders (e.g.
`portraits/2026-08-27`) still work; `..`, absolute paths, and
symlink escapes are now rejected before anything is created.
Covered by a new tests/ suite (tests/test_paths.py), since exercising
nodes.py requires stubbing ComfyUI's runtime (see tests/conftest.py).
Fixesalexopus/ComfyUI-Image-Saver#138
Alexopus