diff --git a/backend/open_webui/routers/models.py b/backend/open_webui/routers/models.py
index 75ee4e723b..75c37b0eb9 100644
--- a/backend/open_webui/routers/models.py
+++ b/backend/open_webui/routers/models.py
@@ -60,6 +60,9 @@ def _safe_static_redirect_path(url: str) -> str | None:
         if decoded == path:
             break
         path = decoded
+    # Fail closed: a value still encoded after the cap would be decoded further downstream.
+    if unquote(path) != path:
+        return None
     if '\x00' in path or '\\' in path:
         return None
     if not path.startswith('/'):
diff --git a/backend/open_webui/routers/terminals.py b/backend/open_webui/routers/terminals.py
index 6a942cf9b2..4c71322bfb 100644
--- a/backend/open_webui/routers/terminals.py
+++ b/backend/open_webui/routers/terminals.py
@@ -43,6 +43,9 @@ def _sanitize_proxy_path(path: str) -> str | None:
         if once == decoded:
             break
         decoded = once
+    # Fail closed: still encoded after the cap means the upstream would decode further into traversal.
+    if unquote(decoded) != decoded:
+        return None
     had_trailing_slash = decoded.endswith('/')
     normalized = posixpath.normpath(decoded)
     # Remove any leading slashes that would reset the base