The Update Conundrum
the.unknown-universe.co.uk
How a “kept back” Proxmox kernel left my home lab exposed to CVE‑2026‑31431 — why I now check upgradable packages and use apt full‑upgrade.

cross-posted from: https://lemmy.ml/post/46701277

I’ve been running my home lab since 2021 and honestly thought my update routine was solid: apt update && apt upgrade, reboot, job done.

Turns out I was wrong. I was checking CVE‑2026‑31431 (Copy Fail) this morning and realised that despite my “successful” updates, I was still running a vulnerable kernel from March.

I’ve had to rethink how I handle host updates. If you’re relying on a standard upgrade and a reboot to keep Proxmox or Debian hosts safe, you might want to check if yours is lying to you as well.

  • endlesseden@pyfedi.deep-rose.orgEnglish
    1·
    28 分钟前

    I honestly don’t know what your talking about. proxmox updated the pve kernels immediately after this CVE was published…

    additionally, this CVE only applies to older (pre-6.17 kernels). unless you are on proxmox 8 or earlier, you are already running a “patched” kernel as the pathway necessary for this was changed and in kernel 7.x and above this CVE doesnt work…

  • nomad@infosec.pubEnglish
    2·
    2 天前

    You only need the reboot if a package update masks the retirement.

    The system is not lying to you, it holds some critical updates back to be installed separately and manually.

    The output shows you which packages have been held back. Just do apt-get install linux-image-amd64 for example, reboot and apt autoremove to remove the old kernel.

  • GreenKnight23@lemmy.worldEnglish
    2·
    2 天前

    from my own experience, apt dist-upgrade removes old kernels, apt upgrade still installed the new kernel, grub updated and booted into the new kernel.

    all dist-upgrade did (for me) was delete the old kernels. which is something I would prefer not to do because it removes any ability to rollback should I absolutely need to.

      • tofu@lemmy.nocturnal.gardenEnglish
        1·
        2 天前

        I don’t know, I’ve seen it several times mentioned in the Proxmox forum. I think it’s more of a theoretical scenario but it’s strongly advised against.

    • TheIPW@lemmy.mlEnglish
      282·
      4 天前

      dist-upgrade and full-upgrade are essentially the same command but yeah, I won’t be using apt upgrade again in the future! Like I said in my post, the joys of being self taught is that you learn by my making mistakes and that’s part of the “fun” 🤣

    • LeTak@feddit.orgEnglish
      52·
      4 天前

      Just don’t use any command in proxmox. Proxmox is designed GUI first. It got an update button in the GUI. Only major releases could need tinkering in the terminal. But even changing repos is now possible in the GUI.

      • endlesseden@pyfedi.deep-rose.orgEnglish
        1·
        32 分钟前

        gotta love that GUI, that bombards you with reminders to subscribe to their paid tier repository constantly and won’t let you update…

        also, provides no methodology to control when it wants to overwrite a config or when a externally added signable dkms exists and creates a prompt during dkms building.

        the gui is nice, but it’s far from perfect…

  • KairuByte@lemmy.dbzer0.comEnglish
    4·
    4 天前

    I mean, you could just use the proxmox UI for updates. Single point for all servers, just click in and hit update. It explicitly runs dist-upgrade already.

  • Suzune@ani.socialEnglish
    61·
    4 天前

    I’ve seen that the patches are only available in the debian-security repository. It’s important to review your repo list in /etc/apt/sources.list.d.

  • BCsven@lemmy.caEnglish
    2·
    4 天前

    The nice thing about zypper is the various patch options and reporting. Gives you a good picture of what CVEs, rating, and if installed, needed, not needed etc. Does Apt have something similar?