After a system update, bad shim signature | Silverblue | F40

[hamrheadcorvette (hammerhead corvette)]

Boot might fail with "vmlinuz[…] has invalid signature" in atomic desktops

Problem In Fedora atomic desktops installations (Silverblue, Kinote, Sway Atomic, Budgie Atomic), which have been setup several releases ago, the system may stop booting and show an error message similar to this: error: …/…/grub-core/loader/i386/efi/linux.c:307:Chd0.gpt2/ostree/fedora-[hash]/vmlinuz-[version] has invalid signature. error: …/…/grub-core/loader/i386/efi/linux.c:205:you need to load the kernel first. Press any key to continue… Cause Fedora atomic desktops currently do not …

Maybe similar ?

Boot issue (grub) in Fedora Silverblue after upgrading (latest known working: 39.20240325.0), error "/ostree/…/vmlinuz[…] has invalid signature", kernel 6.8.6-200.fc39

This sounds exactly like F39/F40: Fails to boot on with "vmlinuz has invalid signature" · Issue #543 · fedora-silverblue/issue-tracker · GitHub. I came across this a few weeks ago on a laptop running Silverblue 38. The successful workaround was to disable Secure Boot as suggested in that thread.

Unable to boot latest Kinoite deployment (bad shim signature)

This is tracked in rebase to SB40 fails to boot on notebook ("vmlinuz has invalid signature") · Issue #543 · fedora-silverblue/issue-tracker · GitHub