Parent directory references not allowed in subfolder path

Error message

Parent directory references not allowed in subfolder path

What it means

Any '/'-separated component equal to '..' in the subfolder is rejected because it references a parent directory, enabling classic directory traversal out of the outputs folder. Raises ValueError with the parent-directory message.

Source

Thrown at invokeai/app/services/image_files/image_files_disk.py:289

        if not resolved_image_path.is_relative_to(resolved_base):
            raise ValueError("Image path outside outputs folder, potential directory traversal detected")

        return resolved_image_path

    @staticmethod
    def _validate_subfolder(subfolder: str) -> None:
        """Validates a subfolder path to prevent directory traversal while allowing controlled subdirectories."""
        if not subfolder:
            return
        if "\\" in subfolder:
            raise ValueError("Backslashes not allowed in subfolder path")
        if subfolder.startswith("/"):
            raise ValueError("Absolute paths not allowed in subfolder path")
        parts = subfolder.split("/")
        for part in parts:
            if part == "..":
                raise ValueError("Parent directory references not allowed in subfolder path")
            if part == "":
                raise ValueError("Empty path segments not allowed in subfolder path")

    def validate_path(self, path: Union[str, Path]) -> bool:
        """Validates the path given for an image or thumbnail."""
        path = path if isinstance(path, Path) else Path(path)
        return path.exists()

    def get_workflow(self, image_name: str, image_subfolder: str = "") -> str | None:
        image = self.get(image_name, image_subfolder=image_subfolder)
        workflow = image.info.get("invokeai_workflow", None)
        if isinstance(workflow, str):
            return workflow
        return None

    def get_graph(self, image_name: str, image_subfolder: str = "") -> str | None:
        image = self.get(image_name, image_subfolder=image_subfolder)
        graph = image.info.get("invokeai_graph", None)

View on GitHub (pinned to 0b6a024f2f)

Solutions

Remove or resolve '..' components from the subfolder before calling
Use a fixed set of allowed subfolder names (allowlist) rather than free-form paths
Normalize with PurePosixPath and reject if any part == '..'

Example fix

// before
sub = f'{user_board}/../images'
// after
sub = posixpath.normpath(user_board)
assert '..' not in PurePosixPath(sub).parts

Defensive patterns

Strategy: validation

Validate before calling

from pathlib import PurePosixPath
def subfolder_is_safe(s: str) -> bool:
    parts = PurePosixPath(s).parts
    return bool(parts) and all(p not in ('..', '.', '') for p in parts) and '\\' not in s
assert subfolder_is_safe('2024/08')

Type guard

def has_no_parent_refs(s: object) -> bool:
    return isinstance(s, str) and '..' not in PurePosixPath(s).parts

Try / catch

try:
    service.save(data, name, image_subfolder=subfolder)
except ValueError as e:
    if 'Parent directory' in str(e):
        raise HTTPException(400, 'Subfolder may not reference parent directories') from e

Prevention

Never build subfolders from unvalidated user input
Allowlist known-good subfolder names instead of free-form paths
Run security tests covering '../' payloads against storage APIs

When it happens

Trigger: Passing image_subfolder like '../secrets', 'a/../b', or '../../etc' to get/save/get_path.

Common situations: User-controlled board names containing '..'; hand-built relative paths; API requests crafted to escape the outputs directory (security probing).

Related errors

AI-assisted analysis of invoke-ai/InvokeAI@0b6a024f2f (2026-08-29). Data as JSON: /api/errors/d2b82a76429b0732. Report an issue: GitHub.