Vulnerability · Published Jul 16, 2026 · Assigned by canonical
CVE-2026-9494ubuntu-pro-client Information Disclosure via Cleartext Bearer Token Exposure in Process Command Line
Medium 5.5
In plain English
A medium-severity security flaw in Ubuntu 14.04 LTS from Canonical. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 4% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
An information disclosure vulnerability exists in Canonical ubuntu-pro-client (formerly ubuntu-advantage-tools). The client validates Ubuntu Pro APT credentials by executing /usr/lib/apt/apt-helper using the download-file command. During this process, the secret bearer token is embedded directly in the cleartext URL component passed via the command-line arguments (argv), resulting in a URL format such as https://bearer:<token>@esm.ubuntu.com/.../. On systems utilizing a default-mounted /proc file system where process-hiding mitigations (such as hidepid) are disabled, an unprivileged local attacker can monitor system processes and read the sensitive bearer token directly from /proc/cmdline while the helper process is actively running. This leaked token can subsequently be used to gain unauthorized access to the victim's Ubuntu Pro or Expanded Security Maintenance (ESM) repositories.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | ubuntu-advantage-tools | 37.2ubuntu~22.04.1 | UBUNTU-CVE-2026-9494 |
| Ubuntu:22.04:LTS | ubuntu-advantage-tools | 37.2ubuntu~22.04.1 | USN-8555-1 |
| Ubuntu:24.04:LTS | ubuntu-advantage-tools | 37.2ubuntu~24.04.1 | USN-8555-1 |
| Ubuntu:24.04:LTS | ubuntu-advantage-tools | 37.2ubuntu~24.04.1 | UBUNTU-CVE-2026-9494 |
| Ubuntu:25.10 | ubuntu-advantage-tools | no fix listed | UBUNTU-CVE-2026-9494 |
| Ubuntu:26.04:LTS | ubuntu-advantage-tools | 37.2ubuntu0.1 | UBUNTU-CVE-2026-9494 |
| Ubuntu:26.04:LTS | ubuntu-advantage-tools | 37.2ubuntu0.1 | USN-8555-1 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Canonical | ubuntu-pro-client (ubuntu-advantage-tools) | 0 – before 37.3 |
| Canonical | Ubuntu 26.04 LTS | see references |
| Canonical | Ubuntu 24.04 LTS | see references |
| Canonical | Ubuntu 22.04 LTS | see references |
| Canonical | Ubuntu 20.04 LTS | see references |
| Canonical | Ubuntu 18.04 LTS | see references |
| Canonical | Ubuntu 16.04 LTS | see references |
| Canonical | Ubuntu 14.04 LTS | see references |
Weakness: CWE-214 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N