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CVE-2026-23953

Linuxcontainers Incus vulnerability

8.7 HIGHPublic exploitEPSS 0.49%
  1. Published22 Jan 2026

Description

Incus is a system container and virtual machine manager. In versions 6.20.0 and below, a user with the ability to launch a container with a custom YAML configuration (e.g a member of the ‘incus’ group) can create an environment variable containing newlines, which can be used to add additional configuration items in the container’s lxc.conf due to newline injection. This can allow adding arbitrary lifecycle hooks, ultimately resulting in arbitrary command execution on the host. Exploiting this issue on IncusOS requires a slight modification of the payload to change to a different writable directory for the validation step (e.g /tmp). This can be confirmed with a second container with /tmp mounted from the host (A privileged action for validation only). A fix is planned for versions 6.0.6 and 6.21.0, but they have not been released at the time of publication.

CVSS 3.1 breakdown

Attack vectorAdjacent
Attack complexityLow
Privileges requiredLow
User interactionNone
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

Affected products

Linuxcontainers Incus≥ 6.1.0 < 6.21.0 · ≤ 6.0.5

Remediation

Fixed in
Linuxcontainers Incus≥ 6.21.0

References

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Frequently asked

Is CVE-2026-23953 being actively exploited?

CVE-2026-23953 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.49%.

How severe is CVE-2026-23953?

CVE-2026-23953 has a CVSS 3.1 base score of 8.7, rated high. EPSS estimates a 0.49% probability of exploitation.

Which products are affected by CVE-2026-23953?

Affected products include Linuxcontainers Incus.

How do I fix CVE-2026-23953?

Upgrade affected software to a fixed version, for example Linuxcontainers Incus 6.21.0 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.