Ubuntu CVE-2026-3888: Timing Flaw in systemd Cleanup Enables Root Privilege Escalation - Cybersecurity88
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A critical Ubuntu vulnerability (CVE-2026-3888) allows attackers to gain root access through a systemd cleanup timing flaw. Learn how it works and how to fix it.

Yet another critical vulnerability in systemd, this time involving snapd. Ubuntu folk are affected.

“A serious security issue has been discovered in Ubuntu, and it is gaining attention in the cybersecurity community. The vulnerability is identified as CVE-2026-3888 and mainly affects Ubuntu Desktop systems from version 24.04 onwards. This flaw is dangerous because it allows an attacker with limited access to gain full root privileges. Root access means complete control over the entire system.”

  • AcornTickler@sh.itjust.works
    4·
    2 小时前

    When I need to create scratch files I usually operate in /tmp. Almost all directories there that I saw were using randomized paths (e.g. UUIDs). I guess this is to prevent problems mentioned in the article. So, I believe this would be a vulnerability of snap, not systemd.

    I use Fedora where /tmp is created as tmpfs, which lives in RAM and is cleared when the system is shut down. I wonder what’s the benefit of Ubuntu’s approach.

    • ChrisG@lemmy.worldOPEnglish
      22·
      1 小时前

      If you think about it for even a minute this is still a glaring cve in systemd, exposed in this case, by misbehaving snapd. systemd still needed to be patched and so did snapd.

      • villainy@lemmy.world
        1·
        5 分钟前

        Ubuntu configures systemd-tmpfiles to delete a snapd tmp dir, snapd runs setuid root and blindly trusts/executes files from a tmp dir it does not manage the life cycle of. Where is the flaw in systemd here?