Description of problem:
I have no idea how this could relate to CUPS (I was doing nothing about the printing at the moment), but I was connecting to the remote computer via ssh.

I have not had key for that computer in my ~/.ssh/known_hosts (or actually, I have remove the previous version of the key).
I have no clue how it relates, but I did nothing about CUPS, but was logging via ssh to the other computer on my LAN, where I have not been before (or where I removed previous key from ~/.ssh/known_hosts).

SELinux is preventing /usr/libexec/gnome-settings-daemon from 'connectto' accesses on the unix_stream_socket /run/cups/cups.sock.

*****  Plugin catchall (100. confidence) suggests   **************************

If you believe that gnome-settings-daemon should be allowed connectto access on the cups.sock unix_stream_socket by default.
Then you should report this as a bug.
You can generate a local policy module to allow this access.
Do
allow this access for now by executing:
# ausearch -c 'gnome-settings-' --raw | audit2allow -M my-gnomesettings
# semodule -i my-gnomesettings.pp

Additional Information:
Source Context                system_u:system_r:xdm_t:s0-s0:c0.c1023
Target Context                system_u:system_r:cupsd_t:s0-s0:c0.c1023
Target Objects                /run/cups/cups.sock [ unix_stream_socket ]
Source                        gnome-settings-
Source Path                   /usr/libexec/gnome-settings-daemon
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           gnome-settings-daemon-3.22.2-5.el7.x86_64
Target RPM Packages           
Policy RPM                    selinux-policy-3.13.1-174.el7.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     (removed)
Platform                      Linux (removed) 3.10.0-737.el7.x86_64 #1 SMP Fri
                              Oct 13 11:19:16 EDT 2017 x86_64 x86_64
Alert Count                   4
First Seen                    2017-10-20 10:26:56 CEST
Last Seen                     2017-10-20 11:02:36 CEST
Local ID                      01ba6e2f-e57d-4806-9817-65a83e41dc9f

Raw Audit Messages
type=AVC msg=audit(1508490156.132:445): avc:  denied  { connectto } for  pid=23628 comm="gnome-settings-" path="/run/cups/cups.sock" scontext=system_u:system_r:xdm_t:s0-s0:c0.c1023 tcontext=system_u:system_r:cupsd_t:s0-s0:c0.c1023 tclass=unix_stream_socket


type=SYSCALL msg=audit(1508490156.132:445): arch=x86_64 syscall=connect success=no exit=EACCES a0=15 a1=a3e578 a2=1a a3=7ffd9c13a7a8 items=0 ppid=23545 pid=23628 auid=4294967295 uid=42 gid=42 euid=42 suid=42 fsuid=42 egid=42 sgid=42 fsgid=42 tty=(none) ses=4294967295 comm=gnome-settings- exe=/usr/libexec/gnome-settings-daemon subj=system_u:system_r:xdm_t:s0-s0:c0.c1023 key=(null)

Hash: gnome-settings-,xdm_t,cupsd_t,unix_stream_socket,connectto

Version-Release number of selected component:
selinux-policy-3.13.1-174.el7.noarch

Additional info:
reporter:       libreport-2.1.11.1
hashmarkername: setroubleshoot
kernel:         3.10.0-737.el7.x86_64
reproducible:   Not sure how to reproduce the problem
type:           libreport