UBUNTU-CVE-2026-81666

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Source
https://ubuntu.com/security/CVE-2026-81666
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-81666.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-81666
Upstream
  • CVE-2026-81666
Published
2026-09-04T10:17:00Z
Modified
2026-10-17T13:01:11Z
Severity
  • 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
  • Ubuntu - medium
Summary
[none]
Details

An integer overflow was found in Corosync's handling of membership commit token messages. The length-validation check for these messages can be bypassed on 32-bit systems due to an integer overflow in the calculation of the expected message length, allowing a crafted network packet to trigger an out-of-bounds memory access that crashes the Corosync daemon. This results in a denial of service for the affected cluster node. The overflow does not occur on 64-bit systems, where the length calculation is correctly performed in 64-bit arithmetic.

References

Affected packages

Ubuntu:16.04:LTS
corosync

Package

Name
corosync
Purl
pkg:deb/ubuntu/corosync?arch=source&distro=xenial

Affected ranges

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

Affected versions

2.*
2.3.4-0ubuntu1
2.3.5-3
2.3.5-3ubuntu1
2.3.5-3ubuntu2
2.3.5-3ubuntu2.1
2.3.5-3ubuntu2.3

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "corosync",
            "binary_version":  "2.3.5-3ubuntu2.3"
        },
        {
            "binary_name":  "corosync-notifyd",
            "binary_version":  "2.3.5-3ubuntu2.3"
        },
        {
            "binary_name":  "libcfg6",
            "binary_version":  "2.3.5-3ubuntu2.3"
        },
        {
            "binary_name":  "libcmap4",
            "binary_version":  "2.3.5-3ubuntu2.3"
        },
        {
            "binary_name":  "libcorosync-common4",
            "binary_version":  "2.3.5-3ubuntu2.3"
        },
        {
            "binary_name":  "libcpg4",
            "binary_version":  "2.3.5-3ubuntu2.3"
        },
        {
            "binary_name":  "libquorum5",
            "binary_version":  "2.3.5-3ubuntu2.3"
        },
        {
            "binary_name":  "libsam4",
            "binary_version":  "2.3.5-3ubuntu2.3"
        },
        {
            "binary_name":  "libtotem-pg5",
            "binary_version":  "2.3.5-3ubuntu2.3"
        },
        {
            "binary_name":  "libvotequorum7",
            "binary_version":  "2.3.5-3ubuntu2.3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-81666.json"
Ubuntu:18.04:LTS
corosync

Package

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

Affected ranges

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

Affected versions

2.*
2.4.2-3build1
2.4.2-3ubuntu1
2.4.3-0ubuntu1
2.4.3-0ubuntu1.1
2.4.3-0ubuntu1.2
2.4.3-0ubuntu1.3

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "corosync",
            "binary_version":  "2.4.3-0ubuntu1.3"
        },
        {
            "binary_name":  "corosync-notifyd",
            "binary_version":  "2.4.3-0ubuntu1.3"
        },
        {
            "binary_name":  "corosync-qdevice",
            "binary_version":  "2.4.3-0ubuntu1.3"
        },
        {
            "binary_name":  "corosync-qnetd",
            "binary_version":  "2.4.3-0ubuntu1.3"
        },
        {
            "binary_name":  "libcfg6",
            "binary_version":  "2.4.3-0ubuntu1.3"
        },
        {
            "binary_name":  "libcmap4",
            "binary_version":  "2.4.3-0ubuntu1.3"
        },
        {
            "binary_name":  "libcorosync-common4",
            "binary_version":  "2.4.3-0ubuntu1.3"
        },
        {
            "binary_name":  "libcpg4",
            "binary_version":  "2.4.3-0ubuntu1.3"
        },
        {
            "binary_name":  "libquorum5",
            "binary_version":  "2.4.3-0ubuntu1.3"
        },
        {
            "binary_name":  "libsam4",
            "binary_version":  "2.4.3-0ubuntu1.3"
        },
        {
            "binary_name":  "libtotem-pg5",
            "binary_version":  "2.4.3-0ubuntu1.3"
        },
        {
            "binary_name":  "libvotequorum8",
            "binary_version":  "2.4.3-0ubuntu1.3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-81666.json"
Ubuntu:20.04:LTS
corosync

Package

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

Affected ranges

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

Affected versions

3.*
3.0.1-2ubuntu1
3.0.2-1ubuntu1
3.0.2-1ubuntu2
3.0.3-2ubuntu1
3.0.3-2ubuntu2
3.0.3-2ubuntu2.1
3.0.3-2ubuntu2.2

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "corosync",
            "binary_version":  "3.0.3-2ubuntu2.2"
        },
        {
            "binary_name":  "corosync-notifyd",
            "binary_version":  "3.0.3-2ubuntu2.2"
        },
        {
            "binary_name":  "corosync-vqsim",
            "binary_version":  "3.0.3-2ubuntu2.2"
        },
        {
            "binary_name":  "libcfg7",
            "binary_version":  "3.0.3-2ubuntu2.2"
        },
        {
            "binary_name":  "libcmap4",
            "binary_version":  "3.0.3-2ubuntu2.2"
        },
        {
            "binary_name":  "libcorosync-common4",
            "binary_version":  "3.0.3-2ubuntu2.2"
        },
        {
            "binary_name":  "libcpg4",
            "binary_version":  "3.0.3-2ubuntu2.2"
        },
        {
            "binary_name":  "libquorum5",
            "binary_version":  "3.0.3-2ubuntu2.2"
        },
        {
            "binary_name":  "libsam4",
            "binary_version":  "3.0.3-2ubuntu2.2"
        },
        {
            "binary_name":  "libvotequorum8",
            "binary_version":  "3.0.3-2ubuntu2.2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-81666.json"
Ubuntu:22.04:LTS
corosync

Package

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

Affected ranges

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

Affected versions

3.*
3.1.2-2ubuntu1
3.1.6-1ubuntu1
3.1.6-1ubuntu1.1
3.1.6-1ubuntu1.2

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "corosync",
            "binary_version":  "3.1.6-1ubuntu1.2"
        },
        {
            "binary_name":  "corosync-notifyd",
            "binary_version":  "3.1.6-1ubuntu1.2"
        },
        {
            "binary_name":  "corosync-vqsim",
            "binary_version":  "3.1.6-1ubuntu1.2"
        },
        {
            "binary_name":  "libcfg7",
            "binary_version":  "3.1.6-1ubuntu1.2"
        },
        {
            "binary_name":  "libcmap4",
            "binary_version":  "3.1.6-1ubuntu1.2"
        },
        {
            "binary_name":  "libcorosync-common4",
            "binary_version":  "3.1.6-1ubuntu1.2"
        },
        {
            "binary_name":  "libcpg4",
            "binary_version":  "3.1.6-1ubuntu1.2"
        },
        {
            "binary_name":  "libquorum5",
            "binary_version":  "3.1.6-1ubuntu1.2"
        },
        {
            "binary_name":  "libsam4",
            "binary_version":  "3.1.6-1ubuntu1.2"
        },
        {
            "binary_name":  "libvotequorum8",
            "binary_version":  "3.1.6-1ubuntu1.2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-81666.json"
Ubuntu:24.04:LTS
corosync

Package

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

Affected ranges

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

Affected versions

3.*
3.1.7-1ubuntu1
3.1.7-1ubuntu2
3.1.7-1ubuntu3
3.1.7-1ubuntu3.1
3.1.7-1ubuntu3.2

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "corosync",
            "binary_version":  "3.1.7-1ubuntu3.2"
        },
        {
            "binary_name":  "corosync-notifyd",
            "binary_version":  "3.1.7-1ubuntu3.2"
        },
        {
            "binary_name":  "corosync-vqsim",
            "binary_version":  "3.1.7-1ubuntu3.2"
        },
        {
            "binary_name":  "libcfg7",
            "binary_version":  "3.1.7-1ubuntu3.2"
        },
        {
            "binary_name":  "libcmap4",
            "binary_version":  "3.1.7-1ubuntu3.2"
        },
        {
            "binary_name":  "libcorosync-common4",
            "binary_version":  "3.1.7-1ubuntu3.2"
        },
        {
            "binary_name":  "libcpg4",
            "binary_version":  "3.1.7-1ubuntu3.2"
        },
        {
            "binary_name":  "libquorum5",
            "binary_version":  "3.1.7-1ubuntu3.2"
        },
        {
            "binary_name":  "libsam4",
            "binary_version":  "3.1.7-1ubuntu3.2"
        },
        {
            "binary_name":  "libvotequorum8",
            "binary_version":  "3.1.7-1ubuntu3.2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-81666.json"
Ubuntu:26.04:LTS
corosync

Package

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

Affected ranges

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

Affected versions

3.*
3.1.9-2ubuntu1
3.1.9-2ubuntu2
3.1.9-2ubuntu3

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "corosync",
            "binary_version":  "3.1.9-2ubuntu3"
        },
        {
            "binary_name":  "corosync-notifyd",
            "binary_version":  "3.1.9-2ubuntu3"
        },
        {
            "binary_name":  "corosync-vqsim",
            "binary_version":  "3.1.9-2ubuntu3"
        },
        {
            "binary_name":  "libcfg7",
            "binary_version":  "3.1.9-2ubuntu3"
        },
        {
            "binary_name":  "libcmap4",
            "binary_version":  "3.1.9-2ubuntu3"
        },
        {
            "binary_name":  "libcorosync-common4",
            "binary_version":  "3.1.9-2ubuntu3"
        },
        {
            "binary_name":  "libcpg4",
            "binary_version":  "3.1.9-2ubuntu3"
        },
        {
            "binary_name":  "libquorum5",
            "binary_version":  "3.1.9-2ubuntu3"
        },
        {
            "binary_name":  "libsam4",
            "binary_version":  "3.1.9-2ubuntu3"
        },
        {
            "binary_name":  "libvotequorum8",
            "binary_version":  "3.1.9-2ubuntu3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-81666.json"
Ubuntu:26.10
corosync

Package

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

Affected ranges

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

Affected versions

3.*
3.1.9-2ubuntu3
3.1.10-2ubuntu2
3.1.10-3ubuntu1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "corosync",
            "binary_version":  "3.1.10-3ubuntu1"
        },
        {
            "binary_name":  "corosync-notifyd",
            "binary_version":  "3.1.10-3ubuntu1"
        },
        {
            "binary_name":  "corosync-vqsim",
            "binary_version":  "3.1.10-3ubuntu1"
        },
        {
            "binary_name":  "libcfg7",
            "binary_version":  "3.1.10-3ubuntu1"
        },
        {
            "binary_name":  "libcmap4",
            "binary_version":  "3.1.10-3ubuntu1"
        },
        {
            "binary_name":  "libcorosync-common4",
            "binary_version":  "3.1.10-3ubuntu1"
        },
        {
            "binary_name":  "libcpg4",
            "binary_version":  "3.1.10-3ubuntu1"
        },
        {
            "binary_name":  "libquorum5",
            "binary_version":  "3.1.10-3ubuntu1"
        },
        {
            "binary_name":  "libsam4",
            "binary_version":  "3.1.10-3ubuntu1"
        },
        {
            "binary_name":  "libvotequorum8",
            "binary_version":  "3.1.10-3ubuntu1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-81666.json"