LXD arbitrary lxc.conf directive injection via NVIDIA instance configuration (CVE-2026-63298) | HOL Guard CVE

Critical · CVSS 9.9CVE-2026-63298

LXD arbitrary lxc.conf directive injection via NVIDIA instance configuration

Answer in brief

CVE-2026-63298 records a Critical severity (CVSS 9.9) vulnerability in LXD arbitrary lxc.conf directive injection via NVIDIA instance configuration. The current sources do not mark it as known exploited. The current feed maps Canonical/LXD (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 12, 2026Updated Sep 11, 2026Source checked Sep 29, 2026First seen by HOL Aug 12, 2026Material review Sep 11, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.9
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 9.9. 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 Canonical/LXD (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:a:canonical:lxd::::::::	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Canonical/LXDgeneric	>=5.0.0 <5.0.8 \|\| >=5.21.0 <5.21.6 \|\| >=4.0.0 <4.0.12	5.0.8, 5.21.6, 4.0.12

Recommended response

Check inventory. Check lockfiles and deployed manifests for Canonical/LXD.
Review the reported fix. Update Canonical/LXD to 5.0.8 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 12, 2026

Sources and claim methodology

GitHub security advisorygithub.com

Upstream source description

An improper neutralization of special elements vulnerability in LXD's NVIDIA instance configuration handling allows an authenticated attacker to inject arbitrary configuration directives. By supplying newline characters within the 'nvidia.driver.capabilities' or 'nvidia.require.*' configuration values, an attacker can manipulate the generated lxc.conf file. This flaw enables the attacker to execute arbitrary code on the host system with the privileges of the LXD daemon.

Quoted source text, attributed separately from HOL analysis.