UBUNTU-CVE-2026-56113

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Source
https://ubuntu.com/security/CVE-2026-56113
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56113.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-56113
Upstream
Published
2026-06-23T17:17:00Z
Modified
2026-06-29T13:56:54.833359923Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • 6.0 (Medium) CVSS_V4 - CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

dhcpcd through 10.3.2, fixed in commit 5733d3c, contains a heap use-after-free vulnerability that allows unauthenticated same-link attackers to crash the daemon by sending a crafted DHCPv6 RENEW reply with RFC6603 OPTIONPDEXCLUDE and both preferred and valid lifetimes set to zero. Attackers acting as or impersonating a DHCPv6 server can trigger dhcp6deprecatedele() to free a delegated child address while an outer TAILQFOREACHSAFE iterator in dhcp6deprecateaddrs() still holds the freed pointer, causing a use-after-free when TAILQ_REMOVE is reached.

References

Affected packages

Ubuntu:24.04:LTS / dhcpcd

Package

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

Affected ranges

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

Affected versions

1:10.*
1:10.0.2-3ubuntu3
1:10.0.5-1
1:10.0.5-2
1:10.0.5-3
1:10.0.5-4
1:10.0.5-5
1:10.0.6-1
1:10.0.6-1ubuntu1
1:10.0.6-1ubuntu2
1:10.0.6-1ubuntu3
1:10.0.6-1ubuntu3.1
1:10.0.6-1ubuntu3.2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "dhcpcd",
            "binary_version": "1:10.0.6-1ubuntu3.2"
        },
        {
            "binary_name": "dhcpcd-base",
            "binary_version": "1:10.0.6-1ubuntu3.2"
        },
        {
            "binary_name": "dhcpcd5",
            "binary_version": "1:10.0.6-1ubuntu3.2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56113.json"

Ubuntu:25.10 / dhcpcd

Package

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

Affected ranges

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

Affected versions

1:10.*
1:10.1.0-8
1:10.1.0-10
1:10.1.0-11
1:10.1.0-12
1:10.2.4-3
1:10.2.4-4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "dhcpcd",
            "binary_version": "1:10.2.4-4"
        },
        {
            "binary_name": "dhcpcd-base",
            "binary_version": "1:10.2.4-4"
        },
        {
            "binary_name": "dhcpcd5",
            "binary_version": "1:10.2.4-4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56113.json"

Ubuntu:26.04:LTS / dhcpcd

Package

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

Affected ranges

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

Affected versions

1:10.*
1:10.2.4-4
1:10.3.0-2
1:10.3.0-3
1:10.3.0-7

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "dhcpcd",
            "binary_version": "1:10.3.0-7"
        },
        {
            "binary_name": "dhcpcd-base",
            "binary_version": "1:10.3.0-7"
        },
        {
            "binary_name": "dhcpcd5",
            "binary_version": "1:10.3.0-7"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56113.json"