There was a somewhat recent security update that fixed the logic of the DisableForwarding option: https://launchpad.net/ubuntu/+source/openssh/1:9.6p1-3ubuntu13.11
I wonder if you have that option configured, and it just recently started to take effect. Can you please share the output of: $ apt policy openssh-server $ sshd -G | grep forward from one of the affected servers? ** Changed in: openssh (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to openssh in Ubuntu. https://bugs.launchpad.net/bugs/2112611 Title: ssh -X and ssh -Y does not work to non-ESM enabled servers iin 22.04 Status in openssh package in Ubuntu: Incomplete Bug description: Until recently I have been able to ssh -X to my machines and run X applications such as synaptic remotely. Within the last two days this broke and I am not 100% sure if it is an issue with xauth or ssh but it will not start X forwarding, debugging just says it fails without much info. However, it works on all ESM enabled machines. These are all Ubuntu 24.04. The only difference I can see is some of the libs that xauth uses appear to be different. But I don't know the root cause, I just know it was working until recently and now it doesn't. ProblemType: Bug DistroRelease: Ubuntu 24.04 Package: ssh (not installed) Uname: Linux 6.15.0 x86_64 ApportVersion: 2.28.1-0ubuntu3.6 Architecture: amd64 CasperMD5CheckResult: unknown CurrentDesktop: MATE Date: Thu Jun 5 20:46:47 2025 SourcePackage: openssh UpgradeStatus: Upgraded to noble on 2024-10-05 (244 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/2112611/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp