CVE-2026-12391 MEDIUM

CVE-2026-12391: ubuntu-pro-client Local Privilege Escalation and Information Disclosure via Symlink Arbitrary File Read in collect-logs

Vendor Canonical
Product ubuntu-pro-client (ubuntu-advantage-tools)
Weakness CWE-59
Published July 16, 2026
Last update July 16, 2026

CVSS base score

5.0/10
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction Required
Confidentiality High
Integrity None

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

July 16, 2026 CVE published
July 16, 2026 Record updated