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.

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.

  • ShortN0te@lemmy.ml
    202·
    16 days ago

    When a kernel update requires a change in dependencies, something Proxmox kernels do frequently, apt just quietly “keeps back” the package. It doesn’t fail, it doesn’t break the system, and it doesn’t trigger a rollback. It just waits for me to notice.

    This should save a click for hopefully everyone.

    Yes obviously, if you do not update the packages then they do not get updated.

    If you do not read the output of a command then you will not notuce that.

    • paris@lemmy.blahaj.zone
      102·
      16 days ago

      The standard upgrade command has this behavior though, which is unexpected to people like me and the author. You need a specific flag to tell apt to actually upgrade everything which is not the behavior I expected.

        • fuckwit_mcbumcrumble@lemmy.dbzer0.comEnglish
          11·
          12 days ago

          Sure in the gigantic wall of text. Also it doesn’t tell you why, or what to do about it. All they’d have to do is say “run dist-upgrade to update these packages.”

          • ShortN0te@lemmy.ml
            11·
            11 days ago

            Sure in the gigantic wall of text. Also it doesn’t tell you why, or what to do about it. All they’d have to do is say “run dist-upgrade to update these packages.”

            It is literally in the summary that gets presented in the last few lines before you have to press Y to continue.

            Since you are already overwhelmed by the wall of text, you would probably not read the suggestion antways.

  • actionjbone@sh.itjust.works
    9·
    16 days ago

    Thanks for sharing this. I’m very confident with Linux, but I hadn’t thought about this!

    Your blog post was concise, too. I hate scrolling forever before finding the solution.

    • TheIPW@lemmy.mlOP
      7·
      16 days ago

      Glad you found it useful. I’m the same, I can’t stand those long posts that make you read a life story before getting to the commands, even worse when a page is riddled by ads or behind a paywall!

      I figured if I’d missed it, a few other people probably had too.

    • TheIPW@lemmy.mlOP
      61·
      16 days ago

      No, apt isn’t just a rename. apt upgrade largely replaces apt-get upgrade, but it’s a bit more aggressive: it may install new packages if required as dependencies (it still won’t remove packages). If an upgrade needs to remove packages to resolve dependencies, use apt full-upgrade (same as apt-get dist-upgrade).

  • Akrenion@slrpnk.net
    1·
    14 days ago

    There’s no point in digital hoarding; it just clutters the boot partition and makes future updates messier.

    I feel personally attacked.