CVE Intelligence
Medium

CVE-2026-9494 — ubuntu-pro-client Information Disclosure via Cleartext Bearer Token Exposure in Process Command Line

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 using the download-file command. During this process, the secret bearer token is embedded directly in the cleartext URL component passed via the command-line arguments (argv), resulting in a URL format such as https://bearer:<token>@esm.ubuntu.com/.../. On systems utilizing a default-mounted /proc file system where process-hiding mitigations (such as hidepid) are disabled, an unprivileged local attacker can monitor system processes and read the sensitive bearer token directly from /proc/cmdline while the helper process is actively running. This leaked token can subsequently be used to gain unauthorized access to the victim's Ubuntu Pro or Expanded Security Maintenance (ESM) repositories.

Published Jul 16, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: canonical

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
—
No EPSS score.
Affects
Canonical
Ubuntu 14.04 LTS and 7 more
CVSS base
5.5
Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Canonical Ubuntu 14.04 LTS, Canonical Ubuntu 16.04 LTS, Canonical Ubuntu 18.04 LTS…).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Canonical Ubuntu 14.04 LTS versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Canonical Ubuntu 16.04 LTS versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Canonical Ubuntu 18.04 LTS versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Canonical Ubuntu 20.04 LTS versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Canonical Ubuntu 22.04 LTS versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Canonical Ubuntu 24.04 LTS versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Canonical Ubuntu 26.04 LTS versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Canonical Ubuntu-pro-client (ubuntu-advantage-tools) < 37.3 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
5.5 CVSS 3.1 Medium 1.8 3.6 security@ubuntu.com via NIST National Vulnerability Database
5.5 CVSS 3.1 Medium — — canonical via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N (score shown at the top: security@ubuntu.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-214

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · canonical/ubuntu-pro-client (ubuntu-advantage-tools), canonical/ubuntu 26.04 lts, canonical/ubuntu 24.04 lts, canonical/
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 5.5
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Awaiting Analysis
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Jul 16, 2026 · canonical

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

1 on the record

Elsewhere on this site

Canonical
every CVE for this vendor
CWE-214
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-8933 snap-confine Local Privilege Escalation via Capabilities Misconfiguration or Flaw in Execution Environment Setup Jul 21, 2026
  • CVE-2026-15226 snapd snap-confine Sandbox Confinement Bypass via Omission of setuid Restriction in Seccomp Templates Jul 21, 2026
  • CVE-2024-5300 AppArmor Base Profile Misconfiguration in snapd Permits Confined Snaps Unauthorized Access to Hashed Passwords via systemd-userdbd Jul 21, 2026
  • CVE-2026-11386 ubuntu-pro-client Input Validation Vulnerability Leading to Arbitrary APT Directive Injection and Remote Code Execution Jul 16, 2026
  • CVE-2026-12391 ubuntu-pro-client Local Privilege Escalation and Information Disclosure via Symlink Arbitrary File Read in collect-logs Jul 16, 2026
  • CVE-2026-12249 Canonical ADSys plaintext HTTP CA certificate retrieval enables trust store poisoning Jun 22, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No FIRST EPSS score.
  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-9494 is "ubuntu-pro-client Information Disclosure via Cleartext Bearer Token Exposure in Process Command Line", rated Medium. It affects Ubuntu 14.04 LTS (Canonical); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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