If

1. Elog is configured to use webserver authentication, and
2. the user reported by the webserver does not exist in the password file, and
3. the "Guest Menu commands" configuration is set in "elogd.cfg", and
4. a logbook is accessed,

then Elog returns with a redirect (302) to the logbook itself, causing the loop.

The fix here is to remove the "Guest Menu commands" configuration from "elogd.cfg".

Source code location: https://bitbucket.org/ritt/elog/src/30ada1df634529c8011c27275c52a05b01b7b3d6/src/elogd.cxx#lines-27599