diff --git a/more_math/Parser/MathExpr.g4 b/more_math/Parser/MathExpr.g4
index 44288a5..c7cd612 100644
--- a/more_math/Parser/MathExpr.g4
+++ b/more_math/Parser/MathExpr.g4
@@ -1383,7 +1383,7 @@ func3:
 		/**
 		  text_image(text, font, size, [max_width], [weight], [rotation_angle], [line_spacing], [italic], [underline]) - renders text to a 2D tensor with values 0-1
 		  - text: text to render; line breaks start new lines
-		  - font: font name to look up in the system fonts, or a path to a font file
+		  - font: font name to look up in the system fonts, or a path to a font file in a system font folder or the ComfyUI input folder
 		  - size: font size in pixels
 		  - max_width: wrap lines wider than this many pixels (default: 0, no wrapping)
 		  - weight: font weight 100-900 as in CSS (default: 400)
diff --git a/more_math/Parser/UnifiedMathVisitor.py b/more_math/Parser/UnifiedMathVisitor.py
index f014efe..344db8c 100644
--- a/more_math/Parser/UnifiedMathVisitor.py
+++ b/more_math/Parser/UnifiedMathVisitor.py
@@ -10,6 +10,7 @@ import math
 import inspect
 import weakref
 import torch.nn.functional as F
+import folder_paths
 from comfy.nested_tensor import NestedTensor
 from comfy.model_management import throw_exception_if_processing_interrupted
 from comfy.k_diffusion import sampling as k_sampling
@@ -190,9 +191,7 @@ def _font_axis_name(axis):
     return str(name).lower()
 
 
-@functools.lru_cache(maxsize=1)
-def _system_fonts():
-    """Index of installed fonts, scanned once per process (fonts installed later need a restart)."""
+def _font_dirs():
     if sys.platform == "win32":
         search_dirs = [os.path.join(os.environ.get("WINDIR", "C:\\Windows"), "Fonts"), os.path.expandvars(r"%LOCALAPPDATA%\Microsoft\Windows\Fonts")]
     elif sys.platform == "darwin":
@@ -205,9 +204,23 @@ def _system_fonts():
             os.path.expanduser("~/.local/share/fonts"),
             os.path.expanduser("~/.fonts"),
         ]
+    return list(dict.fromkeys(search_dirs))
 
+
+def _is_allowed_font_file(path):
+    """Font files given by path must be in a system font folder or in ComfyUI's input folder."""
+    if not os.path.isfile(path):
+        return False
+    path = os.path.normcase(os.path.realpath(path))
+    roots = _font_dirs() + [folder_paths.get_input_directory()]
+    return any(path.startswith(os.path.normcase(os.path.realpath(root)) + os.sep) for root in roots)
+
+
+@functools.lru_cache(maxsize=1)
+def _system_fonts():
+    """Index of installed fonts, scanned once per process (fonts installed later need a restart)."""
     fonts = []
-    for directory in dict.fromkeys(search_dirs):
+    for directory in _font_dirs():
         for root, _, files in os.walk(directory):
             for fname in files:
                 if not fname.lower().endswith((".ttf", ".otf", ".ttc", ".otc")):
@@ -3536,7 +3549,7 @@ class UnifiedMathVisitor(MathExprVisitor):
         tier = _FONT_WEIGHT_TIERS[bisect.bisect_left((150, 250, 350, 450, 550, 650, 750, 850), weight_val)]
         synthetic_italic = synthetic_bold = False
         variation_weight, variation_italic = weight_val, is_italic
-        if os.path.isfile(font_name):
+        if _is_allowed_font_file(font_name):
             font_path = font_name
         else:
             font_path = _find_font(font_name, tier, weight_val, is_italic)
diff --git a/more_math/Parser/inbuilt_symbols.py b/more_math/Parser/inbuilt_symbols.py
index 8bec85f..71d1e3e 100644
--- a/more_math/Parser/inbuilt_symbols.py
+++ b/more_math/Parser/inbuilt_symbols.py
@@ -264,7 +264,7 @@ INBUILT_FUNCTION_META = {
     'interpolate_area': {'min_args': 2, 'max_args': 2, 'signature': 'interpolate_area(x, scale)', 'forms': [['x', 'scale']], 'description': 'resizes x [N, C, ...] with area interpolation. A number scales every spatial dimension; a list is the target spatial size', 'details': '', 'params': {'x': 'tensor shaped [N, C, ...] with 1-3 spatial dimensions', 'scale': 'a number scales every spatial dimension; a list gives the target spatial size'}, 'aliases': []},
     'interpolate_nearest': {'min_args': 2, 'max_args': 2, 'signature': 'interpolate_nearest(x, scale)', 'forms': [['x', 'scale']], 'description': 'resizes x [N, C, ...] with nearest-neighbour interpolation. A number scales every spatial dimension; a list is the target spatial size', 'details': '', 'params': {'x': 'tensor shaped [N, C, ...] with 1-3 spatial dimensions', 'scale': 'a number scales every spatial dimension; a list gives the target spatial size'}, 'aliases': ['interpolate_nearest_exact']},
     'interpolate_nearest_exact': {'min_args': 2, 'max_args': 2, 'signature': 'interpolate_nearest_exact(x, scale)', 'forms': [['x', 'scale']], 'description': 'resizes x [N, C, ...] with nearest-neighbour interpolation. A number scales every spatial dimension; a list is the target spatial size', 'details': '', 'params': {'x': 'tensor shaped [N, C, ...] with 1-3 spatial dimensions', 'scale': 'a number scales every spatial dimension; a list gives the target spatial size'}, 'aliases': ['interpolate_nearest']},
-    'text_image': {'min_args': 3, 'max_args': 9, 'signature': 'text_image(text, font, size, [max_width], [weight], [rotation_angle], [line_spacing], [italic], [underline])', 'forms': [['text', 'font', 'size', '[max_width]', '[weight]', '[rotation_angle]', '[line_spacing]', '[italic]', '[underline]']], 'description': 'renders text to a 2D tensor with values 0-1', 'details': '', 'params': {'text': 'text to render; line breaks start new lines', 'font': 'font name to look up in the system fonts, or a path to a font file', 'size': 'font size in pixels', 'max_width': 'wrap lines wider than this many pixels (default: 0, no wrapping)', 'weight': 'font weight 100-900 as in CSS (default: 400)', 'rotation_angle': 'rotation in degrees, counter-clockwise (default: 0)', 'line_spacing': 'line distance as a multiple of the line height (default: 1)', 'italic': 'truthy for italic text (default: false)', 'underline': 'truthy to underline the text (default: false)'}, 'aliases': []},
+    'text_image': {'min_args': 3, 'max_args': 9, 'signature': 'text_image(text, font, size, [max_width], [weight], [rotation_angle], [line_spacing], [italic], [underline])', 'forms': [['text', 'font', 'size', '[max_width]', '[weight]', '[rotation_angle]', '[line_spacing]', '[italic]', '[underline]']], 'description': 'renders text to a 2D tensor with values 0-1', 'details': '', 'params': {'text': 'text to render; line breaks start new lines', 'font': 'font name to look up in the system fonts, or a path to a font file in a system font folder or the ComfyUI input folder', 'size': 'font size in pixels', 'max_width': 'wrap lines wider than this many pixels (default: 0, no wrapping)', 'weight': 'font weight 100-900 as in CSS (default: 400)', 'rotation_angle': 'rotation in degrees, counter-clockwise (default: 0)', 'line_spacing': 'line distance as a multiple of the line height (default: 1)', 'italic': 'truthy for italic text (default: false)', 'underline': 'truthy to underline the text (default: false)'}, 'aliases': []},
     'as_nested_tensor': {'min_args': 1, 'max_args': 1, 'signature': 'as_nested_tensor(values)', 'forms': [['values']], 'description': 'converts a list to a nested tensor (special object containing tensors of different shapes behaving like a tensor)', 'details': '', 'params': {'values': 'list of tensors; their shapes may differ'}, 'aliases': ['as_nested']},
     'as_nested': {'min_args': 1, 'max_args': 1, 'signature': 'as_nested(values)', 'forms': [['values']], 'description': 'converts a list to a nested tensor (special object containing tensors of different shapes behaving like a tensor)', 'details': '', 'params': {'values': 'list of tensors; their shapes may differ'}, 'aliases': ['as_nested_tensor']},
     'svd': {'min_args': 1, 'max_args': 2, 'signature': 'svd(x, [full_matrices])', 'forms': [['x', '[full_matrices]']], 'description': 'computes the singular value decomposition of x. Returns a list of 3 tensors U, S, Vh such that x = matmul(matmul(U, diagonal_matrix(S, shape(U))), Vh)', 'details': '', 'params': {'x': 'matrix, or a batch of matrices in the last two dimensions', 'full_matrices': 'truthy to return full-size U and Vh (default: false)'}, 'aliases': ['singular_value_decomposition']},
diff --git a/tests/test_unified_visitor_regressions.py b/tests/test_unified_visitor_regressions.py
index c9a9832..0e9bc97 100644
--- a/tests/test_unified_visitor_regressions.py
+++ b/tests/test_unified_visitor_regressions.py
@@ -80,17 +80,12 @@ def test_lambda_calls_require_exact_argument_count(call):
 def test_text_image_size_expression_is_evaluated_once(monkeypatch):
     visitor_module = importlib.import_module("more_math.Parser.UnifiedMathVisitor")
     default_font = ImageFont.load_default()
-    original_isfile = os.path.isfile
     monkeypatch.setattr(
         visitor_module.ImageFont,
         "truetype",
         lambda *args, **kwargs: default_font,
     )
-    monkeypatch.setattr(
-        visitor_module.os.path,
-        "isfile",
-        lambda path: path == "mock-font" or original_isfile(path),
-    )
+    monkeypatch.setattr(visitor_module, "_is_allowed_font_file", lambda path: path == "mock-font")
 
     values = MathDict()
     _visit(
@@ -101,6 +96,15 @@ def test_text_image_size_expression_is_evaluated_once(monkeypatch):
     assert len(values) == 1
 
 
+def test_text_image_rejects_font_path_outside_font_folders(monkeypatch):
+    visitor_module = importlib.import_module("more_math.Parser.UnifiedMathVisitor")
+    monkeypatch.setattr(visitor_module, "_find_font", lambda *args: None)
+    path = os.path.abspath(__file__).replace("\\", "/")
+
+    with pytest.raises(FileNotFoundError):
+        _visit(f'text_image("x", "{path}", 12)', {})
+
+
 def test_stack_list_of_tensors_with_negative_dimension():
     first = torch.tensor([1.0, 2.0])
     second = torch.tensor([3.0, 4.0])
diff --git a/web/inbuilt_symbols.js b/web/inbuilt_symbols.js
index ed031ea..5d354e8 100644
--- a/web/inbuilt_symbols.js
+++ b/web/inbuilt_symbols.js
@@ -267,7 +267,7 @@ export const FUNCTION_META = {
     "interpolate_area": { minArgs: 2, maxArgs: 2, signature: "interpolate_area(x, scale)", forms: [["x", "scale"]], description: "resizes x [N, C, ...] with area interpolation. A number scales every spatial dimension; a list is the target spatial size", details: "", params: {"x": "tensor shaped [N, C, ...] with 1-3 spatial dimensions", "scale": "a number scales every spatial dimension; a list gives the target spatial size"}, aliases: [] },
     "interpolate_nearest": { minArgs: 2, maxArgs: 2, signature: "interpolate_nearest(x, scale)", forms: [["x", "scale"]], description: "resizes x [N, C, ...] with nearest-neighbour interpolation. A number scales every spatial dimension; a list is the target spatial size", details: "", params: {"x": "tensor shaped [N, C, ...] with 1-3 spatial dimensions", "scale": "a number scales every spatial dimension; a list gives the target spatial size"}, aliases: ["interpolate_nearest_exact"] },
     "interpolate_nearest_exact": { minArgs: 2, maxArgs: 2, signature: "interpolate_nearest_exact(x, scale)", forms: [["x", "scale"]], description: "resizes x [N, C, ...] with nearest-neighbour interpolation. A number scales every spatial dimension; a list is the target spatial size", details: "", params: {"x": "tensor shaped [N, C, ...] with 1-3 spatial dimensions", "scale": "a number scales every spatial dimension; a list gives the target spatial size"}, aliases: ["interpolate_nearest"] },
-    "text_image": { minArgs: 3, maxArgs: 9, signature: "text_image(text, font, size, [max_width], [weight], [rotation_angle], [line_spacing], [italic], [underline])", forms: [["text", "font", "size", "[max_width]", "[weight]", "[rotation_angle]", "[line_spacing]", "[italic]", "[underline]"]], description: "renders text to a 2D tensor with values 0-1", details: "", params: {"text": "text to render; line breaks start new lines", "font": "font name to look up in the system fonts, or a path to a font file", "size": "font size in pixels", "max_width": "wrap lines wider than this many pixels (default: 0, no wrapping)", "weight": "font weight 100-900 as in CSS (default: 400)", "rotation_angle": "rotation in degrees, counter-clockwise (default: 0)", "line_spacing": "line distance as a multiple of the line height (default: 1)", "italic": "truthy for italic text (default: false)", "underline": "truthy to underline the text (default: false)"}, aliases: [] },
+    "text_image": { minArgs: 3, maxArgs: 9, signature: "text_image(text, font, size, [max_width], [weight], [rotation_angle], [line_spacing], [italic], [underline])", forms: [["text", "font", "size", "[max_width]", "[weight]", "[rotation_angle]", "[line_spacing]", "[italic]", "[underline]"]], description: "renders text to a 2D tensor with values 0-1", details: "", params: {"text": "text to render; line breaks start new lines", "font": "font name to look up in the system fonts, or a path to a font file in a system font folder or the ComfyUI input folder", "size": "font size in pixels", "max_width": "wrap lines wider than this many pixels (default: 0, no wrapping)", "weight": "font weight 100-900 as in CSS (default: 400)", "rotation_angle": "rotation in degrees, counter-clockwise (default: 0)", "line_spacing": "line distance as a multiple of the line height (default: 1)", "italic": "truthy for italic text (default: false)", "underline": "truthy to underline the text (default: false)"}, aliases: [] },
     "as_nested_tensor": { minArgs: 1, maxArgs: 1, signature: "as_nested_tensor(values)", forms: [["values"]], description: "converts a list to a nested tensor (special object containing tensors of different shapes behaving like a tensor)", details: "", params: {"values": "list of tensors; their shapes may differ"}, aliases: ["as_nested"] },
     "as_nested": { minArgs: 1, maxArgs: 1, signature: "as_nested(values)", forms: [["values"]], description: "converts a list to a nested tensor (special object containing tensors of different shapes behaving like a tensor)", details: "", params: {"values": "list of tensors; their shapes may differ"}, aliases: ["as_nested_tensor"] },
     "svd": { minArgs: 1, maxArgs: 2, signature: "svd(x, [full_matrices])", forms: [["x", "[full_matrices]"]], description: "computes the singular value decomposition of x. Returns a list of 3 tensors U, S, Vh such that x = matmul(matmul(U, diagonal_matrix(S, shape(U))), Vh)", details: "", params: {"x": "matrix, or a batch of matrices in the last two dimensions", "full_matrices": "truthy to return full-size U and Vh (default: false)"}, aliases: ["singular_value_decomposition"] },