CVE-2026-12391

Published Jul 16, 2026

Last updated 2 months ago

CVSS medium 5.0
Ubuntu

Overview

Description
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.
Source
security@ubuntu.com
NVD status
Undergoing Analysis

Risk scores

CVSS 3.1

Type
Secondary
Base score
5
Impact score
3.6
Exploitability score
1.3
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N
Severity
MEDIUM

Weaknesses

security@ubuntu.com
CWE-59

Social media

Hype score
Not currently trending

  1. 🐛 VULNERABILITIES CVE Notify: 🚨 [CVE-2026-12391](https://t.co/WFZNu95cRD) An insecure symlink following vulner... https://t.co/WFZNu95cRD #Vulnerability #CVE #ZeroDay

    @MalwareObserver

    16 Jul 2026

    32 Impressions

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References

Sources include official advisories and independent security research.