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Fencer Vulns
medium 6.2

CVE-2026-40227 json

In 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.

published 2026-04-10 6 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-21402

cvss
6.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

In 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.

Patch / fix

  • systemd systemd 261
  • systemd Debian 14 260.1-1

debian advisories DEBIAN-CVE-2026-40227

  • systemd hummingbird 1 260.1-2.1.hum1
  • systemd-pam hummingbird 1 260.1-2.1.hum1
  • systemd-libs hummingbird 1 260.1-2.1.hum1
  • systemd-udev hummingbird 1 260.1-2.1.hum1
  • systemd-tests hummingbird 1 260.1-2.1.hum1
  • systemd-ukify hummingbird 1 260.1-2.1.hum1
  • systemd-shared hummingbird 1 260.1-2.1.hum1
  • systemd-networkd hummingbird 1 260.1-2.1.hum1

red hat advisories RHSA-2026:7299

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-40227 updated cvss 5.5

systemd: systemd: Denial of Service via malicious IPC API call with null element

  • Red Hat Hardened Images systemd 260.1-2.1.hum1, systemd-pam 260.1-2.1.hum1, systemd-libs 260.1-2.1.hum1, systemd-udev 260.1-2.1.hum1, systemd-tests 260.1-2.1.hum1, systemd-ukify 260.1-2.1.hum1, +14 more
    fixed: vendor fix “This issue can be mitigated by changing the permission of the varsock file located at: ~~~ /run/systemd/io.systemd.Manager ~~~ to be accessible only by trusted or privileged users.” RHSA-2026:7299
  • Red Hat Enterprise Linux 7 systemd, libgudev1, systemd-libs, systemd-sysv, systemd-python, systemd-networkd, +2 more Red Hat Enterprise Linux 8 systemd, systemd-pam, systemd-libs, systemd-udev, systemd-tests, NetworkManager, +16 more Red Hat Enterprise Linux 9 systemd, systemd-pam, systemd-libs, systemd-oomd, systemd-udev, systemd-ukify, +21 more Red Hat Enterprise Linux 10 systemd, rpm-ostree, NetworkManager Red Hat OpenShift Container Platform 4 systemd, systemd-pam, systemd-libs, systemd-oomd, systemd-udev, systemd-tests, +24 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.2 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • systemd systemd

Classification

Weakness
  • CWE-1025 Comparison Using Wrong Factors

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.