Authorization Flaw in LXD (CVE-2026-62420)
Summary
Vulnerability in LXD (CVE-2026-62420). Successful exploitation can lead to full system takeover. Exploitable via POST /1.0/instances/{name}.
Original description
The description as published by the source.
An authorization bypass vulnerability in LXD allows an authenticated attacker to bypass target project security restrictions during cross-project instance migrations. When moving an instance cross-project to a different cluster member via POST /1.0/instances/{name} with migration: true, project: , and target: , the destination node skips all project restriction checks because the request arrives as an internal cluster notification. An attacker can exploit this to introduce disallowed instance configurations into a restricted project.
Source: NIST National Vulnerability Database NVD
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-2026-62420 has been found in LXD.
Attackers can target a specific entry point like POST /1.0/instances/{name} over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.9/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "LXD CVE-2026-62420" on the vendor's site.
CVE-2026-62420 (LXD) — CWE-863 / CVSS v3 9.9
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /1.0/instances/{name}
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.
Incorrect authorization (CWE-863) exists in LXD. Attackers reach the vulnerable code path via POST /1.0/instances/{name}.
Check the vendor advisory for the affected versions of LXD. Attack surface: POST /1.0/instances/{name}.
Severity: Critical (CVSS 9.9/10). 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 POST /1.0/instances/{name} requests with malformed payloads or SQL meta-characters. Run grep -r '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 '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
LXDを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'POST /1.0/instances/{name}' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /1.0/instances/{name}への異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Post-deployment verification verify
Replay attack against POST /1.0/instances/{name} on staging to confirm patch closes the vector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 Step 2 と同じログクエリでアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-62420 lxd
- Ubuntu UBUNTU-CVE-2026-62420 lxd
References
- exploit github.com
- patch security@ubuntu.com
- patch security@ubuntu.com