systemd on Linux: which version fixes what

What it is, and why it is on your server

systemd starts and supervises everything on a modern Linux system, and ships a family of daemons alongside it: systemd-resolved, systemd-journald, systemd-networkd and udev among them.

Why its advisories behave the way they do

• The advisories are usually in the satellites, not in PID 1. systemd-resolved parses DNS responses and systemd-journald parses log input, and those are the components handling data from elsewhere.
• Almost all of it runs as root. An escalation in a systemd component tends to land directly at root rather than needing a second step.
• Patching does not take effect until the unit restarts, and restarting PID 1 is not something to do casually. `systemctl daemon-reexec` handles the manager itself; the satellite services need their own restarts.

Check what you are actually running

The version that matters is the package version, not the upstream one. Distributions backport security fixes without changing the number before the dash, so a release that looks years old is frequently fully patched, and the revision after the dash is the only part that tells you.

dpkg-query -W -f='${Package} ${Version}\n' systemd systemd-resolved 2>/dev/null

rpm -q systemd systemd-resolved

On Debian and Ubuntu, `needrestart -r l` after an upgrade lists the systemd services still running older code.

Fixed versions, per distribution

Each distribution patches on its own schedule and under its own version scheme, so the same CVE has a different answer on each of them. These come from the distributions’ own advisory data, asked per release. Where a release has no fixed version, that is what the advisory says, not a gap in the data.

Advisory data last refreshed 26 September 2026. It is re-read daily.

What this page does not tell you

It does not tell you whether your server is affected. A CVE applying to a package is not the same as a CVE applying to your installation: the fix may already be backported into what you are running, the vulnerable module may not be loaded, or the service may not be reachable from anywhere that matters. Answering that needs the versions on your machine, not a list.

It also carries no count of how many servers are affected. SecAI monitors a small fleet, and a percentage drawn from it would be arithmetic on a sample too small to mean anything. When that changes, the number will appear here and the page will say when it started.

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