Skip to content
Fencer Vulns
high 8.7

CVE-2026-23954 json

Incus container image templating arbitrary host file read and write

published 2026-01-22 9 mo ago modified 2026-06-17 4 mo ago also GHSA-7f67-crqm-jgh7 , GO-2026-4357 , EUVD-2026-3803

cvss
8.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 56%
public exploits
0
none known

Summary

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.

Patch / fix

  • linuxcontainers incus 6.21.0
  • lxd Debian 13 5.0.2+git20231211.1364ae4-9+deb13u3
  • incus Debian 13 6.0.4-2+deb13u4
  • incus Debian 14 6.0.5-8

debian advisories DEBIAN-CVE-2026-23954

  • govulncheck-vulndb openSUSE Leap 15.6 0.0.20260205T172317-150000.1.146.1

suse advisories SUSE-SU-2026:0403-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
  • incus openSUSE Tumbleweed 6.22-1.1

opensuse advisories openSUSE-SU-2026:21483-1openSUSE-SU-2026:10280-1

  • incus Alpine 3.24, Alpine 3.23 6.0.5-r6
  • incus-feature Alpine 3.24, Alpine 3.23 6.21.0-r0

alpine advisories ALPINE-CVE-2026-23954

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2026-23954 updated cvss 8.7

incus: container image templating arbitrary host file read and write

  • Red Hat All currently supported Red Hat products
    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
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
9 mo ago

Exploit prediction

0.78% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/lxc/incus/security/advisories/GHSA-7f67-crqm-jgh7 referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/user-attachments/files/24473599/template_arbitrary_write.sh referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.7 CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
GitHub 3.1 8.7 CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
go github.com/lxc/incus/v6/cmd/incusd
all versions
 no fix listed
go github.com/lxc/incus
all versions
 no fix listed
go github.com/lxc/incus/v6
>=6.1.0
 no fix listed

Affected products

  • lxc incus

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

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.