Comfy-Org/ComfyUI · error · Exception

**** ERROR: Saving image outside the output folder is not al

Error message

**** ERROR: Saving image outside the output folder is not allowed.\n full_output_folder: {full_output_folder}\n         output_dir: {output_dir}

What it means

get_save_image_path splits filename_prefix into subfolder + filename and joins them under output_dir; if the normalized prefix contains '../' components, full_output_folder resolves outside output_dir and is_within_directory fails. The node logs the error (paths included) and raises, preventing writes outside the designated output tree.

Source

Thrown at folder_paths.py:557

        input = input.replace("%hour%", str(now.tm_hour).zfill(2))
        input = input.replace("%minute%", str(now.tm_min).zfill(2))
        input = input.replace("%second%", str(now.tm_sec).zfill(2))
        return input

    if "%" in filename_prefix:
        filename_prefix = compute_vars(filename_prefix, image_width, image_height)

    subfolder = os.path.dirname(os.path.normpath(filename_prefix))
    filename = os.path.basename(os.path.normpath(filename_prefix))

    full_output_folder = os.path.join(output_dir, subfolder)

    if not is_within_directory(output_dir, full_output_folder):
        err = "**** ERROR: Saving image outside the output folder is not allowed." + \
              "\n full_output_folder: " + os.path.abspath(full_output_folder) + \
              "\n         output_dir: " + output_dir
        logging.error(err)
        raise Exception(err)

    try:
        counter = max(filter(lambda a: os.path.normcase(a[1][:-1]) == os.path.normcase(filename) and a[1][-1] == "_", map(map_filename, os.listdir(full_output_folder))))[0] + 1
    except ValueError:
        counter = 1
    except FileNotFoundError:
        os.makedirs(full_output_folder, exist_ok=True)
        counter = 1
    return full_output_folder, filename, counter, subfolder, filename_prefix

def get_input_subfolders() -> list[str]:
    """Returns a list of all subfolder paths in the input directory, recursively.

    Returns:
        List of folder paths relative to the input directory, excluding the root directory
    """
    input_dir = get_input_directory()
    folders = []

View on GitHub (pinned to 1c6d8d45b3)

Solutions

1. Use a prefix with only subdirectory names (e.g. 'ComfyUI/myrun') relative to the output directory
2. To change the output root, configure the server's output directory setting instead of traversing with '../'
3. If automating, sanitize prefixes: strip '..' and absolute-path components before submission

Example fix

# before
prefix = "../../shared/renders"
# after
prefix = "renders"  # saved under <output_dir>/renders/

import os
n = os.path.normpath(filename_prefix)
assert not os.path.isabs(n) and ".." not in n.split(os.sep), "prefix must stay inside the output dir"

def is_safe_prefix(prefix: str) -> bool:
    n = os.path.normpath(prefix)
    return not os.path.isabs(n) and ".." not in n.split(os.sep)

When it happens

Trigger: A SaveImage/SaveVideo filename_prefix like '../../tmp/out' that escapes the output directory; workflow JSON with traversal-style prefixes; API-submitted prompts with crafted prefixes.

Common situations: Users trying to save directly to an arbitrary absolute path via the prefix; copied workflows from setups where the prefix implied a different directory structure; security probing of the queue API.

Related errors

• destination escapes base directory
• Invalid folder name {folder_name!r}: resolves outside of {ba
• Invalid file path: {!r}
• Unknown user:
• System User prefix not allowed

AI-assisted analysis of Comfy-Org/ComfyUI@1c6d8d45b3 (2026-08-14). Data as JSON: /api/errors/911d10dc9ea24922. Report an issue: GitHub.