Critical severity · published Aug 21, 2026
CVE-2026-63343
Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root
9.9
CVSS
0.5%
EPSS
No
On KEV
Description
Incus is a system container and virtual machine manager. Prior to version 7.3.0, a malicious image containing a `metadata.yaml` symlink pointing to an arbitrary host path allows an authenticated Incus user to read or overwrite any file on the host as root via the instance metadata API. The `exec-output` and `templates/` paths were patched in a prior release using `Lstat` rejection and `os.OpenRoot` confinement; `metadata.yaml` was not included in either patch and remains exploitable. Version 7.3.0 patches the issue.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 41% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
IN
incus · lxc
< 7.3.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-63343
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-63343
github.com
https://github.com/lxc/incus/security/advisories/GHSA-fmjx-5j3g-997p
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