CVE-2026-12391
MediumCVSS 5.0Summary
A vulnerability in the ubuntu-pro-client (formerly ubuntu-advantage-tools) pro collect-logs command allows an unprivileged local attacker to create a symbolic link to root-readable files (e.g., /etc/shadow). When an administrator runs the tool, it follows the symlink and includes the sensitive file contents in the diagnostic archive, which is then accessible to the attacker.
Risk Assessment
The organization risks complete disclosure of system secrets such as user passwords or private keys, potentially leading to privilege escalation and system compromise.
Recommendation
Immediately update the ubuntu-pro-client package to the latest patched version and restrict access to temporary directories used by the tool.
Other vulnerabilities in ubuntu-pro-client
See all- CVE-2026-9494Medium
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 with the secret bearer token embedded directly in the cleartext URL passed via command-line arguments (argv). On systems with a default-mounted /proc filesystem where process-hiding mitigations (hidepid) are disabled, an unprivileged local attacker can monitor system processes and read the sensitive bearer token from /proc/cmdline while the helper process is running.
- CVE-2026-11386Critical
An input validation vulnerability in ubuntu-pro-client (formerly ubuntu-advantage-tools) allows injection of arbitrary APT repository configurations and installation of malicious packages with root privileges. The issue stems from missing validation of contract server data used to generate APT source files and execute apt-get install commands.
Original NVD description (English source)
An insecure symlink following vulnerability exists in Canonical ubuntu-pro-client (formerly ubuntu-advantage-tools) within the pro collect-logs command framework. The utility creates or utilizes predictable temporary file paths or user-accessible log directories when gathering diagnostic information without verifying the file type or ownership. An unprivileged local attacker can exploit this behavior by creating a symbolic link (symlink) at a predictable destination path pointing to an arbitrary, root-readable file (such as /etc/shadow or private files within /root). When a root administrator or operator subsequently executes the pro collect-logs command, the tool follows the user-controlled symlink, reads the target file, and compresses its contents into the resulting diagnostic support archive. Because the output archive remains readable by the unprivileged user, the attacker can extract and read the sensitive root-owned files, leading to a complete information disclosure of system secrets.