Strange log message and node not found for anonymous I have a node found at the teaser of front-end for both admin and anonymous users. However, going to the node details page using anonymous user leads to 404 error while it works fine with admin.

The log message details is strange as shown in the following screen shot:

 

What is custom_404_page? I'm afraid of it is a hacking against the website.

I tried to clear all cache, I disabled XMLsitemap module. I could not able to determine where is the origin of custom_404_page.

Also in the log and after clearing it, and the trying to visit this node's details, this is the only log message available. i.e there is no other messages or warnings.
Check your custom 404 configuration at admin/config/system/site-information.

Also check if this custom configuration is directing users to a Panels page (check Structure &gt; Panels or Structure &gt; Pages if you have Panels and Page Manager installed). They may be handling different custom 404 pages for different roles. Perhaps the Panel variant that handles the 404 page for anonymous is missing or redirecting to a non-existing page.