Vulnerability in github.com/canonical/lxd (CVE-2026-34178)
Summary
Vulnerability in github.com/canonical/lxd (CVE-2026-34178). Successful exploitation can lead to full system takeover. Exploitable via index.yaml.
Original description
The description as published by the source.
Summary
LXD instance backup import validates project restrictions against backup/index.yaml embedded in the tar archive, but creates the actual instance from backup/container/backup.yaml extracted to the storage volume. Because these are separate, independently attacker-controlled files within the same tar archive, an attacker with instance-creation rights in a restricted project can craft a backup where index.yaml contains clean configuration (passing all restriction checks) while backup.yaml contains security.privileged=true, raw.lxc host filesystem mounts, and restricted device types. The instance is created from the unchecked backup.yaml, bypassing all project restriction enforcement.
Details
LXD projects support a restricted=true mode that enforces security boundaries on what instances within the project can do. These restrictions include blocking security.privileged=true containers, raw.lxc / raw.apparmor overrides, and device passthrough (GPU, USB, PCI, unix-char). These restrictions are intended to prevent container escape vectors regardless of user privilege level within the project.
The backup import path has two distinct configuration sources within a single tar archive:
backup/index.yaml- A quick-access metadata file read bybackup.GetInfo()atbackup/backup_info.go:68. This is the config checked against project restrictions.backup/container/backup.yaml- The full instance configuration extracted to the storage volu…
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-34178 has been found in github.com/canonical/lxd.
Attackers can target a specific entry point like index.yaml over the network to misuse the product.
Successful exploitation can lead to full system takeover.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "github.com/canonical/lxd CVE-2026-34178" on the vendor's site.
CVE-2026-34178 (github.com/canonical/lxd) — CWE-20
Attack vector: remote (network-reachable) / no user interaction
Attack surface: index.yaml / backup.yaml / raw.lxc / raw.apparmor
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-20) exists in github.com/canonical/lxd. Attackers reach the vulnerable code path via index.yaml.
Check the vendor advisory for the affected versions of github.com/canonical/lxd. Attack surface: index.yaml / backup.yaml / raw.lxc / raw.apparmor.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/canonical/lxd' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'github.com/canonical/lxd' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/canonical/lxdを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-34178 incus Fixed in: 6.0.4-2+deb13u6
- Ubuntu UBUNTU-CVE-2026-34178 incus
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com