diff --git a/frontend/src/composables/useIcons.ts b/frontend/src/composables/useIcons.ts
index 30c42a44..5b2b7bb7 100644
--- a/frontend/src/composables/useIcons.ts
+++ b/frontend/src/composables/useIcons.ts
@@ -5,34 +5,50 @@ import { icons as iconsApi } from '@/api/client'
 const iconNames = ref<string[]>([])
 const svgCache: Record<string, string> = {}  // name → normalised SVG string
 let listPromise: Promise<void> | null = null
+const BLOCKED_URL_SCHEMES = ['javascript:', 'data:', 'http:', 'https:']
+const URL_FUNCTION_ATTRIBUTES = new Set([
+  'fill',
+  'stroke',
+  'filter',
+  'clip-path',
+  'mask',
+  'marker-start',
+  'marker-mid',
+  'marker-end',
+  'cursor',
+])
 
-function isDangerousHref(raw: string): boolean {
-  // Normalize obfuscated schemes like "java\nscript:" before checking.
-  const normalized = raw
-    .trim()
-    .toLowerCase()
-    .replace(/[\u0000-\u001f\u007f\s]+/g, '')
-  return normalized.startsWith('javascript:')
+function isBlockedUrlReference(rawValue: string): boolean {
+  const normalized = rawValue.toLowerCase().replace(/[\u0000-\u0020]+/g, '')
+  return normalized.startsWith('//') || BLOCKED_URL_SCHEMES.some((scheme) => normalized.startsWith(scheme))
+}
+
+function hasBlockedCssUrlFunction(value: string): boolean {
+  for (const match of value.matchAll(/url\(([^)]*)\)/gi)) {
+    const rawRef = (match[1] || '').trim().replace(/^['"]|['"]$/g, '')
+    if (isBlockedUrlReference(rawRef)) return true
+  }
+  return false
 }
 
 function sanitizeSvg(raw: string): string {
   const parser = new DOMParser()
   const doc = parser.parseFromString(raw, 'image/svg+xml')
   const svg = doc.documentElement
+
   if (!svg || svg.tagName.toLowerCase() !== 'svg') return ''
 
-  // Remove executable or HTML-capable elements
-  doc.querySelectorAll('script, foreignObject').forEach((el) => el.remove())
-  // Remove SMIL animation elements that can mutate attributes post-sanitization.
-  doc.querySelectorAll('animate, animateMotion, animateTransform, set').forEach((el) => el.remove())
+  // Drop executable, externally embeddable, or dynamic mutation content.
+  doc.querySelectorAll('script,style,foreignObject,iframe,object,embed,audio,video,animate,set,animateMotion,animateTransform').forEach((el) => el.remove())
 
-  // Remove dangerous attributes and fixed dimensions
-  for (const el of Array.from(doc.querySelectorAll('*'))) {
+  for (const el of [svg, ...Array.from(doc.querySelectorAll('*'))]) {
     for (const attr of Array.from(el.attributes)) {
       const name = attr.name.toLowerCase()
-      const value = attr.value
+      const localName = (attr.localName || attr.name).toLowerCase()
+      const lowerValue = attr.value.toLowerCase()
+      const normalizedValue = attr.value.toLowerCase().replace(/[\u0000-\u0020]+/g, '')
 
-      if (name === 'width' || name === 'height') {
+      if (el === svg && (name === 'width' || name === 'height')) {
         el.removeAttribute(attr.name)
         continue
       }
@@ -42,7 +58,20 @@ function sanitizeSvg(raw: string): string {
         continue
       }
 
-      if ((name === 'href' || name === 'xlink:href') && isDangerousHref(value)) {
+      if (name === 'style' && (lowerValue.includes('url(') || lowerValue.includes('@import'))) {
+        el.removeAttribute(attr.name)
+        continue
+      }
+
+      if ((localName === 'href' || localName === 'src') && (
+        normalizedValue.startsWith('//') ||
+        BLOCKED_URL_SCHEMES.some((scheme) => normalizedValue.startsWith(scheme))
+      )) {
+        el.removeAttribute(attr.name)
+        continue
+      }
+
+      if (URL_FUNCTION_ATTRIBUTES.has(localName) && hasBlockedCssUrlFunction(attr.value)) {
         el.removeAttribute(attr.name)
       }
     }
diff --git a/obs/config.py b/obs/config.py
index 7f825302..d22415bb 100644
--- a/obs/config.py
+++ b/obs/config.py
@@ -144,6 +144,7 @@ def _import_legacy_env_vars() -> None:
     present, prefer an explicitly supplied OPENTWS_* value for compatibility.
     """
     legacy_prefix = "OPENTWS_"
+    legacy_prefix_upper = legacy_prefix.upper()
     new_prefix = "OBS_"
     docker_defaults = {
         "OBS_CONFIG": "/data/config.yaml",
@@ -151,7 +152,7 @@ def _import_legacy_env_vars() -> None:
     }
 
     for key, value in list(os.environ.items()):
-        if not key.startswith(legacy_prefix):
+        if not key.upper().startswith(legacy_prefix_upper):
             continue
         mapped_key = f"{new_prefix}{key[len(legacy_prefix) :]}"
         existing_key = _get_existing_env_key_case_insensitive(mapped_key)
@@ -173,6 +174,10 @@ def _resolve_default_db_path(default_path: str = "/data/obs.db") -> str:
     return default_path
 
 
+def _is_builtin_default_db_path(path: str) -> bool:
+    return Path(path).as_posix() == "/data/obs.db"
+
+
 _import_legacy_env_vars()
 
 
@@ -223,11 +228,20 @@ def _inject_database_path_fallback(cls, data: Any) -> Any:
             return result
 
         if isinstance(database_value, dict):
-            has_path = any(isinstance(key, str) and key.lower() == "path" for key in database_value)
-            if not has_path:
+            path_key = next(
+                (key for key in database_value if isinstance(key, str) and key.lower() == "path"),
+                None,
+            )
+            if path_key is None:
                 merged_database = dict(database_value)
                 merged_database["path"] = default_path
                 result[database_key] = merged_database
+            else:
+                current_path = database_value.get(path_key)
+                if isinstance(current_path, str) and _is_builtin_default_db_path(current_path):
+                    merged_database = dict(database_value)
+                    merged_database[path_key] = default_path
+                    result[database_key] = merged_database
 
         return result