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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-12391
StatePUBLISHED
Assignercanonical
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-16 13:16:24 UTC
Updated2026-07-16 14:16:48 UTC
DescriptionAn 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.

Risk And Classification

Primary CVSS: v3.1 5 MEDIUM from [email protected]

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

EPSS: 0.001550000 probability, percentile 0.050810000 (date 2026-07-20)

Problem Types: CWE-59 | CWE-59 CWE-59 Improper link resolution before file access ('link following')

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N
3.1CNACVSS5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Canonical Ubuntu-pro-client Ubuntu-advantage-tools affected 37.3 python Linux
CNA Canonical Ubuntu 26.04 LTS unaffected 37.2ubuntu0.1 dpkg Linux
CNA Canonical Ubuntu 24.04 LTS unaffected 37.2ubuntu~24.04.1 dpkg Linux
CNA Canonical Ubuntu 22.04 LTS unaffected 37.2ubuntu~22.04.1 dpkg Linux
CNA Canonical Ubuntu 20.04 LTS unaffected 37.1ubuntu0~20.04.1 dpkg Linux
CNA Canonical Ubuntu 18.04 LTS unaffected 37.1ubuntu0~18.04.1 dpkg Linux
CNA Canonical Ubuntu 16.04 LTS unaffected 37.1ubuntu0~16.04.1 dpkg Linux

References

ReferenceSourceLinkTags
ubuntu.com/security/CVE-2026-12391 [email protected] ubuntu.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Mateusz Gierblinski (en)

© CVE.report 2026

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