linux-image-3.16.0-10-amd64 missing on security.debian.org

[mabi <mabi@protonmail.ch>]

Hello,

I still have an older Debian 8.11 system running and would like to apply the latest security patches. Unfortunately it seems like some packages are missing from http://security.debian.org as you can see in the apt-get update/upgrade" below:

$ sudo apt-get update
Ign http://ftp.ch.debian.org jessie InRelease
Hit http://ftp.ch.debian.org jessie Release.gpg
Hit http://ftp.ch.debian.org jessie Release
Get:1 http://security.debian.org jessie/updates InRelease [44.9 kB]
Hit http://ftp.ch.debian.org jessie/main amd64 Packages
Hit http://ftp.ch.debian.org jessie/non-free amd64 Packages
Hit http://ftp.ch.debian.org jessie/contrib amd64 Packages
Get:2 http://security.debian.org jessie/updates/main amd64 Packages [781 kB]
Hit http://ftp.ch.debian.org jessie/contrib Translation-en
Hit http://ftp.ch.debian.org jessie/main Translation-en
Hit http://ftp.ch.debian.org jessie/non-free Translation-en
Get:3 http://security.debian.org jessie/updates/contrib amd64 Packages [2,506 B]
Get:4 http://security.debian.org jessie/updates/non-free amd64 Packages [4,702 B]
Get:5 http://security.debian.org jessie/updates/contrib Translation-en [1,211 B]
Get:6 http://security.debian.org jessie/updates/main Translation-en [401 kB]
Get:7 http://security.debian.org jessie/updates/non-free Translation-en [11.8 kB]
Fetched 1,247 kB in 2s (512 kB/s)
Reading package lists... Done

$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
  linux-image-amd64 xen-linux-system-amd64
The following packages will be upgraded:
  linux-image-3.16.0-10-amd64 xen-linux-system-3.16.0-10-amd64
2 upgraded, 0 newly installed, 0 to remove and 2 not upgraded.
Need to get 35.0 MB of archives.
After this operation, 27.6 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
Err http://security.debian.org/ jessie/updates/main xen-linux-system-3.16.0-10-amd64 amd64 3.16.81-1
  404  Not Found [IP: 151.101.2.132 80]
Err http://security.debian.org/ jessie/updates/main linux-image-3.16.0-10-amd64 amd64 3.16.81-1
  404  Not Found [IP: 151.101.2.132 80]
E: Failed to fetch http://security.debian.org/pool/updates/main/l/linux/xen-linux-system-3.16.0-10-amd64_3.16.81-1_amd64.deb  404  Not Found [IP: 151.101.2.132 80]

E: Failed to fetch http://security.debian.org/pool/updates/main/l/linux/linux-image-3.16.0-10-amd64_3.16.81-1_amd64.deb  404  Not Found [IP: 151.101.2.132 80]

E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

I have the following entries in my /etc/apt/sources.list file:

deb http://ftp.ch.debian.org/debian jessie main non-free contrib
deb http://security.debian.org/ jessie/updates main contrib non-free

Any idea how I can fix that?

Thank you very much in advance.

Best regards,
Mabi