Merge pull request from GHSA-p737-p57g-4cpr

jupyter_server/log.py

@@ -50,7 +50,11 @@ def log_request(handler):
         ns["referer"] = request.headers.get("Referer", "None")
         msg = msg + " referer={referer}"
     if status >= 500 and status != 502:
-        # log all headers if it caused an error
-        log_method(json.dumps(dict(request.headers), indent=2))
+        # Log a subset of the headers if it caused an error.
+        headers = {}
+        for header in ['Host', 'Accept', 'Referer', 'User-Agent']:
+            if header in request.headers:
+                headers[header] = request.headers[header]
+        log_method(json.dumps(headers, indent=2))
     log_method(msg.format(**ns))
     prometheus_log_method(handler)