UBUNTU-CVE-2026-48689

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Source
https://ubuntu.com/security/CVE-2026-48689
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48689.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-48689
Upstream
Downstream
Related
Published
2026-05-26T19:16:00Z
Modified
2026-06-16T05:00:07Z
Severity
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

FastNetMon Community Edition through 1.2.9 contains an off-by-one heap-based buffer overflow in the dynamic_binary_buffer_t class (src/dynamic_binary_buffer.hpp). Five methods (append_dynamic_buffer, append_data_as_pointer, append_data_as_object_ptr, memcpy_from_ptr, memcpy_from_object_ptr) use an incorrect bounds check of the form 'if (offset + length > maximum_internal_storage_size + 1)' instead of the correct 'if (offset + length > maximum_internal_storage_size)'. This allows writing exactly one byte past the end of the heap-allocated buffer. The class is used pervasively in BGP message encoding/decoding, NetFlow template processing, and Flow Spec NLRI construction. An attacker who can send network traffic (NetFlow, sFlow, IPFIX, or BGP) to a FastNetMon instance can trigger this overflow, potentially achieving arbitrary code execution by corrupting heap metadata. Notably, the append_byte() method uses the correct bounds check, confirming the inconsistency.

References

Affected packages

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
Fixed
1.2.6-1ubuntu0.1~esm1

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

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
    "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-2026-48689.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-2026-48689.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
Fixed
1.2.8+git20250911-2ubuntu0.1~esm1

Affected versions

1.*
1.2.8+git20250911-1
1.2.8+git20250911-1build1
1.2.8+git20250911-1build2
1.2.8+git20250911-2

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
    "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-2026-48689.json"