Vulnerability in ubuntu-advantage-tools (UBUNTU-CVE-2026-11386)
Summary
Vulnerability in ubuntu-advantage-tools (UBUNTU-CVE-2026-11386). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 37.2ubuntu~22.04.1 or later.
Original description
The description as published by the source.
An input validation and injection vulnerability exists in Canonical ubuntu-pro-client (formerly ubuntu-advantage-tools). The client constructs APT source files (such as /etc/apt/sources.list.d/ubuntu-.list or their DEB822 equivalents) using data received directly from the contract server response via the directives.suites[] and directives.aptURL fields. Because the client utilizes Python's str.format() to write these files without performing escaping, validation, or newline character filtering, a malicious or tampered contract response containing embedded newline (\n) characters can successfully inject arbitrary, attacker-controlled deb configuration lines into root-owned APT sources. When combined with the unvalidated additionalPackages[] field—which is passed positionally into a root-executed apt-get install command—an attacker capable of spoofing or manipulating the contract response (e.g., via a compromised internal infrastructure, an intercepted connection utilizing a trusted CA, or local logical bugs) can force the client to fetch and install malicious packages. This ultimately leads to arbitrary code execution with root privileges on the affected system. This component is preinstalled on supported Ubuntu Server releases and auto-attaches by default on cloud provider Ubuntu Pro images.
Source: OSV.dev (Open Source Vulnerabilities) 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 UBUNTU-CVE-2026-11386 has been found in ubuntu-advantage-tools.
Successful exploitation can lead to full system takeover.
What to do: upgrade ubuntu-advantage-tools to 37.2ubuntu~22.04.1 or later.
If unsure, ask your IT team or search "ubuntu-advantage-tools UBUNTU-CVE-2026-11386" on the vendor's site.
UBUNTU-CVE-2026-11386 (ubuntu-advantage-tools)
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 37.2ubuntu~22.04.1 — apply immediately
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 (unclassified) exists in ubuntu-advantage-tools.
Check the vendor advisory for the affected versions of ubuntu-advantage-tools.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to 37.2ubuntu~22.04.1.
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 'ubuntu-advantage-tools' . 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
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1Identify exposure identify
grep -r 'ubuntu-advantage-tools' . | 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
ubuntu-advantage-toolsを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade ubuntu-advantage-tools to 37.2ubuntu~22.04.1ステージング環境で 37.2ubuntu~22.04.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-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
References
- advisory ubuntu.com
- report ubuntu.com
- report cve.org