CVE-2026-23954: high-severity vulnerability in lxc incus
Incus container image templating arbitrary host file read and write
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.7epss 0.8%
Incus is a system container and virtual machine manager. Versions 6.21.0 and below allow a user with the ability to launch a container with a custom image (e.g a member of the ‘incus’ group) to use directory traversal or symbolic links in the templating functionality to achieve host arbitrary file read, and host arbitrary file write. This ultimately results in arbitrary command execution on the host. When using an image with a metadata.yaml containing templates, both the source and target paths are not checked for symbolic links or directory traversal. This can also be exploited in IncusOS. 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/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
Affected products
lxc · incusRelated CVEs — lxc incus
In the same product, most dangerous first.
CVE-2026-48769CRITICALIncus has an arbitrary file write on its client due to trusted image hashEPSS 0.8%CVE-2026-48755CRITICALIncus has an argument injection in backup compression algorithm leading to AFW and ACEEPSS 0.8%CVE-2026-48752CRITICALIncus has arbitrary file read+write on host via templates/ symlink in malicious imageEPSS 0.8%CVE-2026-48750CRITICALIncus has an arbitrary file write on host via `exec-output` symlink in crafted imageEPSS 0.8%CVE-2026-48749CRITICALIncus has an arbitrary file read+write on host via rootfs/ symlink in malicious imageEPSS 0.8%CVE-2026-48753CRITICALIncus has an arbitrary file write via path traversal in S3 multipart uploadEPSS 0.7%
References
https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7215https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7294https://github.com/lxc/incus/security/advisories/GHSA-7f67-crqm-jgh7https://github.com/user-attachments/files/24473599/template_arbitrary_write.shhttps://github.com/user-attachments/files/24473601/templates_arbitrary_write.patch