diff --git a/scripts/patch_upload_compat.py b/scripts/patch_upload_compat.py
new file mode 100644
index 0000000..baefec8
--- /dev/null
+++ b/scripts/patch_upload_compat.py
@@ -0,0 +1,96 @@
+#!/usr/bin/env python3
+from pathlib import Path
+import re
+import sys
+
+app_path = Path(sys.argv[1]) if len(sys.argv) > 1 else Path('/opt/virtuality/web/app.py')
+if not app_path.exists():
+    raise SystemExit(f'app.py not found: {app_path}')
+
+text = app_path.read_text()
+changed = []
+
+safe_name_helper = r'''
+
+def safe_upload_filename(filename: str, allowed_suffixes: tuple[str, ...], fallback_prefix: str) -> str | None:
+    original = Path(filename or "").name.strip()
+    suffix = Path(original).suffix.lower()
+    if suffix not in allowed_suffixes:
+        return None
+    stem = Path(original).stem.strip()
+    stem = re.sub(r"\s+", "-", stem)
+    stem = re.sub(r"[^a-zA-Z0-9_.-]", "_", stem)
+    stem = stem.strip("._-")
+    if not stem:
+        stem = fallback_prefix
+    stem = stem[:120]
+    name = f"{stem}{suffix}"
+    if not re.fullmatch(r"[a-zA-Z0-9][a-zA-Z0-9_.-]{0,180}\.[a-zA-Z0-9]{2,8}", name):
+        name = f"{fallback_prefix}{suffix}"
+    return name
+'''
+
+if 'def safe_upload_filename(' not in text:
+    marker = '\n\ndef safe_iso_filename(filename: str) -> str | None:'
+    if marker not in text:
+        raise SystemExit('safe_iso_filename marker not found')
+    text = text.replace(marker, safe_name_helper + marker, 1)
+    changed.append('safe upload filename helper added')
+else:
+    changed.append('safe upload filename helper already present')
+
+old_iso = r'''def safe_iso_filename(filename: str) -> str | None:
+    name = Path(filename or "").name.strip().replace(" ", "-")
+    name = re.sub(r"[^a-zA-Z0-9_.-]", "_", name)
+    if not name.lower().endswith(".iso"):
+        return None
+    if not re.fullmatch(r"[a-zA-Z0-9][a-zA-Z0-9_.-]{1,180}\.iso", name):
+        return None
+    return name
+'''
+new_iso = r'''def safe_iso_filename(filename: str) -> str | None:
+    return safe_upload_filename(filename, (".iso",), "virtuality-iso")
+'''
+if old_iso in text:
+    text = text.replace(old_iso, new_iso, 1)
+    changed.append('ISO filename sanitizer relaxed')
+elif 'return safe_upload_filename(filename, (".iso",), "virtuality-iso")' in text:
+    changed.append('ISO filename sanitizer already relaxed')
+else:
+    changed.append('ISO filename sanitizer replacement skipped')
+
+old_disk = r'''def safe_disk_image_filename(filename: str) -> str | None:
+    name = Path(filename or "").name.strip().replace(" ", "-")
+    name = re.sub(r"[^a-zA-Z0-9_.-]", "_", name)
+    if not name.lower().endswith((".img", ".raw", ".qcow2")):
+        return None
+    if not re.fullmatch(r"[a-zA-Z0-9][a-zA-Z0-9_.-]{1,180}\.(img|raw|qcow2)", name, re.IGNORECASE):
+        return None
+    return name
+'''
+new_disk = r'''def safe_disk_image_filename(filename: str) -> str | None:
+    return safe_upload_filename(filename, (".img", ".raw", ".qcow2"), "virtuality-disk")
+'''
+if old_disk in text:
+    text = text.replace(old_disk, new_disk, 1)
+    changed.append('disk image filename sanitizer relaxed')
+elif 'return safe_upload_filename(filename, (".img", ".raw", ".qcow2"), "virtuality-disk")' in text:
+    changed.append('disk image filename sanitizer already relaxed')
+else:
+    changed.append('disk image filename sanitizer not found yet')
+
+# Make upload errors more explicit when temp/filesystem fails after multipart parsing.
+text = text.replace(
+    '"error": f"Ошибка загрузки ISO: {exc}"}, status_code=500)',
+    '"error": f"Ошибка загрузки ISO: {exc}. Проверь свободное место, права на /var/lib/virtuality/iso и временный каталог /var/lib/virtuality/tmp."}, status_code=500)'
+)
+text = text.replace(
+    '"error": f"Ошибка загрузки образа: {exc}"}, status_code=500)',
+    '"error": f"Ошибка загрузки образа: {exc}. Проверь свободное место, права на /var/lib/virtuality/disk-images и временный каталог /var/lib/virtuality/tmp."}, status_code=500)'
+)
+changed.append('upload error messages clarified')
+
+app_path.write_text(text)
+print('upload compatibility patch applied:')
+for item in changed:
+    print(f'- {item}')