[Fix] Add max_depth guard to BFL _read_image_bytes recursive function

Use the standard depth/max_depth pattern with DEFAULT_MAX_RECURSE_DEPTH
to guard the recursive list-unwrapping in _read_image_bytes, matching
the existing pattern used by _read_all_bytes in vertex_imagen.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

litellm/llms/black_forest_labs/image_edit/transformation.py

@@ -14,6 +14,7 @@ from typing import TYPE_CHECKING, Any, Dict, List, Optional, Tuple, Union
 import httpx
 from httpx._types import RequestFiles
 
+from litellm.constants import DEFAULT_MAX_RECURSE_DEPTH
 from litellm.llms.base_llm.image_edit.transformation import BaseImageEditConfig
 from litellm.secret_managers.main import get_secret_str
 from litellm.types.images.main import ImageEditOptionalRequestParams
@@ -189,17 +190,22 @@ class BlackForestLabsImageEditConfig(BaseImageEditConfig):
         endpoint = self._get_model_endpoint(model)
         return f"{base_url}{endpoint}"
 
-    def _read_image_bytes(self, image: Any) -> bytes:
+    def _read_image_bytes(
+        self,
+        image: Any,
+        depth: int = 0,
+        max_depth: int = DEFAULT_MAX_RECURSE_DEPTH,
+    ) -> bytes:
         """Read image bytes from various input types."""
-        # Unwrap nested lists iteratively to avoid recursion
-        for _ in range(10):
-            if isinstance(image, list):
-                image = image[0]
-            else:
-                break
-
+        if depth > max_depth:
+            raise ValueError(
+                f"Max recursion depth {max_depth} reached while reading image bytes for Black Forest Labs image edit."
+            )
         if isinstance(image, bytes):
             return image
+        elif isinstance(image, list):
+            # If it's a list, take the first image
+            return self._read_image_bytes(image[0], depth=depth + 1, max_depth=max_depth)
         elif isinstance(image, str):
             if image.startswith(("http://", "https://")):
                 # Download image from URL

tests/code_coverage_tests/recursive_detector.py

@@ -44,6 +44,7 @@ IGNORE_FUNCTIONS = [
     "extract_text_from_a2a_message",  # max depth set (default 10) to prevent infinite recursion in A2A message parsing.
     "_convert_to_json_serializable_dict",  # max depth set (default 20) and circular reference protection to prevent infinite recursion.
     "dict",  # max depth set. _LiteLLMParamsDictView.dict() calls builtin dict(), not itself.
+    "_read_image_bytes",  # max depth set.
 ]