🛡️ CVE-2026-12391

🟡 CVSS 5.0 — Medium ✅ No Known Exploit CWE-59 NVD
5.0
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity none, availability none.

Weakness class

CVE-2026-12391 is classified as CWE-59: Link Following. The software follows symbolic or hard links without verifying their target, so a planted link can redirect an operation to a sensitive file.

Affected software

CVE-2026-12391 is recorded against 1 package.

  • unknown

Timeline and source

Published on 16 July 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

ubuntu.com

Details

Severity MEDIUM
CVSS Score 5.0
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N
CWE CWE-59
Public Exploit ✅ No
Source NVD
Published 2026-07-16
Updated 2026-08-11
Modified 2026-07-16
Fix URL N/A

Affected Packages

Software From version Fixed in
unknown

Similar Threats

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