CVE-2026-40227
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn systemd 260 before 261, a local unprivileged user can trigger an assert via an IPC API call with an array or map that has a null element.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA local unprivileged user can trigger an assertion failure in systemd versions 260 and earlier by sending a specially crafted IPC API call containing an array or map with a null element, causing a denial of service via process crash.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data= 260CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed systemd versionRun `systemctl --version` or `systemd --version` to display the systemd version numberAffected if The version shown is 260 or earlier (e.g., 260, 259, 258, etc.)
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Verify systemd is the running init systemRun `systemctl is-system-running` or check if PID 1 is systemd via `ps -p 1 -o comm=`Affected if Systemd is actively running as the system manager (output is 'running' or shows 'systemd' as PID 1)
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Confirm systemd IPC sockets existCheck for the presence of systemd socket files in /run/systemd/ (e.g., `ls -la /run/systemd/`)Affected if IPC-related socket directories or files exist in /run/systemd/ (such as /run/systemd/private, /run/systemd/notify, or similar)
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Verify local user access to systemConfirm you have a local unprivileged user account on the systemAffected if A local unprivileged user account exists on the machine
You are affected if systemd version 260 or earlier is installed and running, making IPC sockets available for a local unprivileged user to trigger the assertion failure.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade systemd to version 261 or later to receive the fix; alternatively, restrict local unprivileged access to systemd IPC sockets as a defense-in-depth measure until patching is feasible.
systemd 261 or later
- Upgrade systemd from version 260 to version 261 or later
- Verify the upgrade by checking systemd version with: systemctl --version
- Test that affected IPC API functionality works as expected after upgrade
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-40227 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-40227 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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