Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root (CVE-2026-63343) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-63343

Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root

Answer in brief

CVE-2026-63343 records a Unknown severity vulnerability in Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root. The current sources do not mark it as known exploited. The current feed maps lxc/incus (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 21, 2026Updated Aug 21, 2026Source checked Aug 22, 2026First seen by HOL Aug 21, 2026Material review Aug 21, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps lxc/incus (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
lxc/incusgeneric	< 7.3.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for lxc/incus.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 21, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 21, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 21, 2026

Sources and claim methodology

GitHub security advisorygithub.com

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.