Info Disclosure in Canonical Ubuntu Pro Client via Cleartext Token
CVE-2026-9494 Published on July 16, 2026

ubuntu-pro-client Information Disclosure via Cleartext Bearer Token Exposure in Process Command Line
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.

NVD

Vulnerability Analysis

CVE-2026-9494 is exploitable with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.

Attack Vector:
LOCAL
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
NONE
Availability Impact:
NONE

Weakness Type

Invocation of Process Using Visible Sensitive Information

A process is invoked with sensitive command-line arguments, environment variables, or other elements that can be seen by other processes on the operating system. Many operating systems allow a user to list information about processes that are owned by other users. Other users could see information such as command line arguments or environment variable settings. When this data contains sensitive information such as credentials, it might allow other users to launch an attack against the software or related resources.


Affected Versions

Canonical ubuntu-pro-client (ubuntu-advantage-tools): Canonical Ubuntu 26.04 LTS: Canonical Ubuntu 24.04 LTS: Canonical Ubuntu 22.04 LTS: Canonical Ubuntu 20.04 LTS: Canonical Ubuntu 18.04 LTS: Canonical Ubuntu 16.04 LTS: Canonical Ubuntu 14.04 LTS: