Skip to content
Fencer Vulns
medium 5.5

CVE-2026-9494 json

ubuntu-pro-client Information Disclosure via Cleartext Bearer Token Exposure in Process Command Line

published 2026-07-16 3 mo ago modified 2026-07-16 3 mo ago also EUVD-2026-44910

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits
0
none known

Summary

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.

Patch / fix

  • Canonical ubuntu-pro-client (ubuntu-advantage-tools) 37.3
  • Canonical Ubuntu 26.04 LTS 37.2ubuntu0.1
  • Canonical Ubuntu 24.04 LTS 37.2ubuntu~24.04.1
  • Canonical Ubuntu 22.04 LTS 37.2ubuntu~22.04.1
  • Canonical Ubuntu 20.04 LTS 37.1ubuntu0~20.04.1
  • Canonical Ubuntu 18.04 LTS 37.1ubuntu0~18.04.1
  • Canonical Ubuntu 16.04 LTS 37.1ubuntu0~16.04.1
  • Canonical Ubuntu 14.04 LTS 19.7ubuntu0.1
  • ubuntu-advantage-tools Ubuntu 22.04 LTS 37.2ubuntu~22.04.1
  • ubuntu-advantage-tools Ubuntu 24.04 LTS 37.2ubuntu~24.04.1
  • ubuntu-advantage-tools Ubuntu 26.04 LTS 37.2ubuntu0.1

ubuntu advisories UBUNTU-CVE-2026-9494

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected products

  • Canonical ubuntu-pro-client (ubuntu-advantage-tools)
  • Canonical Ubuntu 26.04 LTS
  • Canonical Ubuntu 24.04 LTS
  • Canonical Ubuntu 22.04 LTS
  • Canonical Ubuntu 20.04 LTS
  • Canonical Ubuntu 18.04 LTS
  • Canonical Ubuntu 16.04 LTS
  • Canonical Ubuntu 14.04 LTS

Classification

Weakness
  • CWE-214 Invocation of Process Using Visible Sensitive Information

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.