UBUNTU-CVE-2026-124740

See a problem?
Please try reporting it to the source first.
Source
https://ubuntu.com/security/CVE-2026-124740
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-124740.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-124740
Upstream
  • CVE-2026-124740
Published
2026-11-13T00:00:00Z
Modified
2026-11-13T21:05:18Z
Severity
  • 4.3 (Medium) CVSS_V3 - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

A flaw was found in BusyBox's udhcpc6 DHCPv6 client. A malicious server on the local network can trigger a use-after-free condition by responding with a crafted Dynamic Host Configuration Protocol for IPv6 (DHCPv6) reply packet lacking usable address options. This issue causes the client to read stale heap memory, which can result in a Denial of Service (DoS) due to an application crash or disclose previously assigned network address data in subsequent discovery requests.

References

Affected packages

Ubuntu:20.04:LTS
busybox

Package

Name
busybox
Purl
pkg:deb/ubuntu/busybox?arch=source&distro=focal

Affected ranges

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

Affected versions

1:1.*
1:1.30.1-4ubuntu4
1:1.30.1-4ubuntu5
1:1.30.1-4ubuntu6
1:1.30.1-4ubuntu6.1
1:1.30.1-4ubuntu6.2
1:1.30.1-4ubuntu6.3
1:1.30.1-4ubuntu6.4
1:1.30.1-4ubuntu6.5

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "busybox",
            "binary_version": "1:1.30.1-4ubuntu6.5"
        },
        {
            "binary_name": "busybox-initramfs",
            "binary_version": "1:1.30.1-4ubuntu6.5"
        },
        {
            "binary_name": "busybox-static",
            "binary_version": "1:1.30.1-4ubuntu6.5"
        },
        {
            "binary_name": "busybox-syslogd",
            "binary_version": "1:1.30.1-4ubuntu6.5"
        },
        {
            "binary_name": "udhcpc",
            "binary_version": "1:1.30.1-4ubuntu6.5"
        },
        {
            "binary_name": "udhcpd",
            "binary_version": "1:1.30.1-4ubuntu6.5"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-124740.json"
Ubuntu:22.04:LTS
busybox

Package

Name
busybox
Purl
pkg:deb/ubuntu/busybox?arch=source&distro=jammy

Affected ranges

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

Affected versions

1:1.*
1:1.30.1-6ubuntu3
1:1.30.1-7ubuntu1
1:1.30.1-7ubuntu2
1:1.30.1-7ubuntu3
1:1.30.1-7ubuntu3.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "busybox",
            "binary_version": "1:1.30.1-7ubuntu3.1"
        },
        {
            "binary_name": "busybox-initramfs",
            "binary_version": "1:1.30.1-7ubuntu3.1"
        },
        {
            "binary_name": "busybox-static",
            "binary_version": "1:1.30.1-7ubuntu3.1"
        },
        {
            "binary_name": "busybox-syslogd",
            "binary_version": "1:1.30.1-7ubuntu3.1"
        },
        {
            "binary_name": "udhcpc",
            "binary_version": "1:1.30.1-7ubuntu3.1"
        },
        {
            "binary_name": "udhcpd",
            "binary_version": "1:1.30.1-7ubuntu3.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-124740.json"
Ubuntu:24.04:LTS
busybox

Package

Name
busybox
Purl
pkg:deb/ubuntu/busybox?arch=source&distro=noble

Affected ranges

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

Affected versions

1:1.*
1:1.36.1-3ubuntu1
1:1.36.1-6ubuntu1
1:1.36.1-6ubuntu3
1:1.36.1-6ubuntu3.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "busybox",
            "binary_version": "1:1.36.1-6ubuntu3.1"
        },
        {
            "binary_name": "busybox-initramfs",
            "binary_version": "1:1.36.1-6ubuntu3.1"
        },
        {
            "binary_name": "busybox-static",
            "binary_version": "1:1.36.1-6ubuntu3.1"
        },
        {
            "binary_name": "busybox-syslogd",
            "binary_version": "1:1.36.1-6ubuntu3.1"
        },
        {
            "binary_name": "udhcpc",
            "binary_version": "1:1.36.1-6ubuntu3.1"
        },
        {
            "binary_name": "udhcpd",
            "binary_version": "1:1.36.1-6ubuntu3.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-124740.json"
Ubuntu:26.04:LTS
busybox

Package

Name
busybox
Purl
pkg:deb/ubuntu/busybox?arch=source&distro=resolute

Affected ranges

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

Affected versions

1:1.*
1:1.37.0-4ubuntu1
1:1.37.0-7ubuntu1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "busybox",
            "binary_version": "1:1.37.0-7ubuntu1"
        },
        {
            "binary_name": "busybox-initramfs",
            "binary_version": "1:1.37.0-7ubuntu1"
        },
        {
            "binary_name": "busybox-static",
            "binary_version": "1:1.37.0-7ubuntu1"
        },
        {
            "binary_name": "busybox-syslogd",
            "binary_version": "1:1.37.0-7ubuntu1"
        },
        {
            "binary_name": "udhcpc",
            "binary_version": "1:1.37.0-7ubuntu1"
        },
        {
            "binary_name": "udhcpd",
            "binary_version": "1:1.37.0-7ubuntu1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-124740.json"
Ubuntu:26.10
busybox

Package

Name
busybox
Purl
pkg:deb/ubuntu/busybox?arch=source&distro=stonking

Affected ranges

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

Affected versions

1:1.*
1:1.37.0-7ubuntu1
1:1.37.0-10.1ubuntu2
1:1.37.0-10.1ubuntu3
1:1.38.0-3ubuntu1
1:1.38.0-3ubuntu3
1:1.38.0-3ubuntu4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "busybox",
            "binary_version": "1:1.38.0-3ubuntu4"
        },
        {
            "binary_name": "busybox-static",
            "binary_version": "1:1.38.0-3ubuntu4"
        },
        {
            "binary_name": "busybox-syslogd",
            "binary_version": "1:1.38.0-3ubuntu4"
        },
        {
            "binary_name": "udhcpc",
            "binary_version": "1:1.38.0-3ubuntu4"
        },
        {
            "binary_name": "udhcpd",
            "binary_version": "1:1.38.0-3ubuntu4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-124740.json"
Ubuntu:Pro:14.04:LTS
busybox

Package

Name
busybox
Purl
pkg:deb/ubuntu/busybox?arch=source&distro=esm-infra-legacy%2Ftrusty

Affected ranges

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

Affected versions

1:1.*
1:1.20.0-8.1ubuntu1
1:1.20.0-9ubuntu1
1:1.20.0-9ubuntu2
1:1.21.0-1ubuntu1
1:1.21.0-1ubuntu1.4
1:1.21.0-1ubuntu1.4+esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "busybox",
            "binary_version": "1:1.21.0-1ubuntu1.4+esm1"
        },
        {
            "binary_name": "busybox-initramfs",
            "binary_version": "1:1.21.0-1ubuntu1.4+esm1"
        },
        {
            "binary_name": "busybox-static",
            "binary_version": "1:1.21.0-1ubuntu1.4+esm1"
        },
        {
            "binary_name": "busybox-syslogd",
            "binary_version": "1:1.21.0-1ubuntu1.4+esm1"
        },
        {
            "binary_name": "udhcpc",
            "binary_version": "1:1.21.0-1ubuntu1.4+esm1"
        },
        {
            "binary_name": "udhcpd",
            "binary_version": "1:1.21.0-1ubuntu1.4+esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-124740.json"
Ubuntu:Pro:16.04:LTS
busybox

Package

Name
busybox
Purl
pkg:deb/ubuntu/busybox?arch=source&distro=esm-infra%2Fxenial

Affected ranges

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

Affected versions

1:1.*
1:1.22.0-15ubuntu1
1:1.22.0-15ubuntu1.4
1:1.22.0-15ubuntu1.4+esm1
1:1.22.0-15ubuntu1.4+esm2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "busybox",
            "binary_version": "1:1.22.0-15ubuntu1.4+esm2"
        },
        {
            "binary_name": "busybox-initramfs",
            "binary_version": "1:1.22.0-15ubuntu1.4+esm2"
        },
        {
            "binary_name": "busybox-static",
            "binary_version": "1:1.22.0-15ubuntu1.4+esm2"
        },
        {
            "binary_name": "busybox-syslogd",
            "binary_version": "1:1.22.0-15ubuntu1.4+esm2"
        },
        {
            "binary_name": "udhcpc",
            "binary_version": "1:1.22.0-15ubuntu1.4+esm2"
        },
        {
            "binary_name": "udhcpd",
            "binary_version": "1:1.22.0-15ubuntu1.4+esm2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-124740.json"
Ubuntu:Pro:18.04:LTS
busybox

Package

Name
busybox
Purl
pkg:deb/ubuntu/busybox?arch=source&distro=esm-infra%2Fbionic

Affected ranges

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

Affected versions

1:1.*
1:1.22.0-19ubuntu2
1:1.27.2-1ubuntu3
1:1.27.2-1ubuntu4
1:1.27.2-2ubuntu2
1:1.27.2-2ubuntu3
1:1.27.2-2ubuntu3.1
1:1.27.2-2ubuntu3.2
1:1.27.2-2ubuntu3.3
1:1.27.2-2ubuntu3.4
1:1.27.2-2ubuntu3.4+esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "busybox",
            "binary_version": "1:1.27.2-2ubuntu3.4+esm1"
        },
        {
            "binary_name": "busybox-initramfs",
            "binary_version": "1:1.27.2-2ubuntu3.4+esm1"
        },
        {
            "binary_name": "busybox-static",
            "binary_version": "1:1.27.2-2ubuntu3.4+esm1"
        },
        {
            "binary_name": "busybox-syslogd",
            "binary_version": "1:1.27.2-2ubuntu3.4+esm1"
        },
        {
            "binary_name": "udhcpc",
            "binary_version": "1:1.27.2-2ubuntu3.4+esm1"
        },
        {
            "binary_name": "udhcpd",
            "binary_version": "1:1.27.2-2ubuntu3.4+esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-124740.json"