UBUNTU-CVE-2026-48693

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Source
https://ubuntu.com/security/CVE-2026-48693
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48693.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-48693
Upstream
Published
2026-05-26T17:16:00Z
Modified
2026-06-15T20:15:15Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

FastNetMon Community Edition through 1.2.9 is vulnerable to a local symlink attack via predictable file paths in /tmp. The statistics file path defaults to '/tmp/fastnetmon.dat' (src/fastnetmon.cpp line 159). The print_screen_contents_into_file() function (src/fastnetmon_logic.cpp line 2186) opens this path with std::ios::trunc without checking for symlinks or using O_NOFOLLOW. Additionally, the chmod() call on line 2190 always operates on cli_stats_file_path regardless of which file_path parameter was passed (a bug that applies wrong permissions), and the umask is set to 0 during daemonization (src/fastnetmon.cpp line 1821), making all created files world-writable. A local attacker can exploit this to overwrite arbitrary files as the FastNetMon process user (typically root).

References

Affected packages

Ubuntu:18.04:LTS / fastnetmon

Package

Name
fastnetmon
Purl
pkg:deb/ubuntu/fastnetmon?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.1.3+dfsg-3
1.1.3+dfsg-4
1.1.3+dfsg-6build1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "fastnetmon",
            "binary_version": "1.1.3+dfsg-6build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48693.json"

Ubuntu:Pro:20.04:LTS / fastnetmon

Package

Name
fastnetmon
Purl
pkg:deb/ubuntu/fastnetmon?arch=source&distro=esm-apps%2Ffocal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.1.4-1
1.1.4-1build3
1.1.4-1build4
1.1.4-1build5
1.1.4-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "fastnetmon",
            "binary_version": "1.1.4-1ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48693.json"

Ubuntu:Pro:24.04:LTS / fastnetmon

Package

Name
fastnetmon
Purl
pkg:deb/ubuntu/fastnetmon?arch=source&distro=esm-apps%2Fnoble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.2.5-1
1.2.6-1
1.2.6-1build1
1.2.6-1build2
1.2.6-1build3
1.2.6-1build4
1.2.6-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "fastnetmon",
            "binary_version": "1.2.6-1ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48693.json"

Ubuntu:25.10 / fastnetmon

Package

Name
fastnetmon
Purl
pkg:deb/ubuntu/fastnetmon?arch=source&distro=questing

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.2.8-1build1
1.2.8-1build2
1.2.8+git20250911-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "fastnetmon",
            "binary_version": "1.2.8+git20250911-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48693.json"

Ubuntu:Pro:26.04:LTS / fastnetmon

Package

Name
fastnetmon
Purl
pkg:deb/ubuntu/fastnetmon?arch=source&distro=esm-apps%2Fresolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.2.8+git20250911-1
1.2.8+git20250911-1build1
1.2.8+git20250911-1build2
1.2.8+git20250911-2
1.2.8+git20250911-2ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "fastnetmon",
            "binary_version": "1.2.8+git20250911-2ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48693.json"