UBUNTU-CVE-2026-126366

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Source
https://ubuntu.com/security/CVE-2026-126366
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126366.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-126366
Upstream
Published
2026-11-13T00:00:00Z
Modified
2026-11-13T21:05:26Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

MessagePack for Ruby is an implementation of the MessagePack binary serialization format. Prior to 1.8.7, the Java-platform msgpack gem for JRuby allocated arrays and byte buffers directly from attacker-controlled array32, str32, and bin32 declared sizes before confirming that corresponding elements or bytes were available. A short MessagePack header could therefore trigger a very large allocation or sustained heap growth when an application decoded untrusted input through MessagePack.unpack or MessagePack::Unpacker, potentially exhausting the shared JVM heap. map32 and declared counts at or above 2^31 did not use the affected allocation behavior. This issue is fixed in version 1.8.7.

References

Affected packages

Ubuntu:16.04:LTS
ruby-msgpack

Package

Name
ruby-msgpack
Purl
pkg:deb/ubuntu/ruby-msgpack?arch=source&distro=xenial

Affected ranges

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

Affected versions

0.*
0.6.2-1build1
0.6.2-1build2
0.6.2-1build3
0.6.2-1build4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "ruby-msgpack",
            "binary_version": "0.6.2-1build4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126366.json"
Ubuntu:18.04:LTS
ruby-msgpack

Package

Name
ruby-msgpack
Purl
pkg:deb/ubuntu/ruby-msgpack?arch=source&distro=bionic

Affected ranges

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

Affected versions

1.*
1.0.0-1
1.1.0-1
1.1.0-1build1
1.1.0-1build2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "ruby-msgpack",
            "binary_version": "1.1.0-1build2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126366.json"
Ubuntu:20.04:LTS
ruby-msgpack

Package

Name
ruby-msgpack
Purl
pkg:deb/ubuntu/ruby-msgpack?arch=source&distro=focal

Affected ranges

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

Affected versions

1.*
1.1.0-1build2
1.1.0-1build3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "ruby-msgpack",
            "binary_version": "1.1.0-1build3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126366.json"
Ubuntu:22.04:LTS
ruby-msgpack

Package

Name
ruby-msgpack
Purl
pkg:deb/ubuntu/ruby-msgpack?arch=source&distro=jammy

Affected ranges

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

Affected versions

1.*
1.1.0-2build1
1.1.0-2build2
1.4.2-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "ruby-msgpack",
            "binary_version": "1.4.2-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126366.json"
Ubuntu:24.04:LTS
ruby-msgpack

Package

Name
ruby-msgpack
Purl
pkg:deb/ubuntu/ruby-msgpack?arch=source&distro=noble

Affected ranges

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

Affected versions

1.*
1.4.2-2build2
1.4.2-2build3
1.4.2-2build4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "ruby-msgpack",
            "binary_version": "1.4.2-2build4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126366.json"
Ubuntu:26.04:LTS
ruby-msgpack

Package

Name
ruby-msgpack
Purl
pkg:deb/ubuntu/ruby-msgpack?arch=source&distro=resolute

Affected ranges

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

Affected versions

1.*
1.7.2-1.1
1.8.0-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "ruby-msgpack",
            "binary_version": "1.8.0-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126366.json"
Ubuntu:26.10
ruby-msgpack

Package

Name
ruby-msgpack
Purl
pkg:deb/ubuntu/ruby-msgpack?arch=source&distro=stonking

Affected ranges

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

Affected versions

1.*
1.8.0-1
1.8.3-1
1.8.4-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "ruby-msgpack",
            "binary_version": "1.8.4-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126366.json"