UBUNTU-CVE-2026-55851

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Source

https://ubuntu.com/security/CVE-2026-55851

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55851.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-55851

Upstream

CVE-2026-55851

Published

2026-07-21T22:17:00Z

Modified

2026-07-29T10:18:49.936431767Z

Severity

8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final up to (but not including) 4.2.16.Final, and 4.1.0.Final up to (but not including) 4.1.135, the HAProxyMessageDecoder in Netty's codec-haproxy module performs protocol version detection by reading the 13th byte as a signed Java byte and widening it to int without masking; a PROXY protocol v2 binary prefix followed by version byte 0xFF sign-extends to -1, collides with the decoder's need-more-data sentinel, and causes ByteToMessageDecoder to accumulate inbound bytes in an unbounded cumulation buffer until direct memory is exhausted. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

References

Affected packages

Ubuntu:Pro:14.04:LTS

netty

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1:3.*

1:3.2.6.Final-2

1:3.2.6.Final-2+deb8u2build0.14.04.1~esm1

1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1",
            "binary_name": "libnetty-java"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55851.json"

Ubuntu:Pro:16.04:LTS

netty

Package

Name: netty
Purl: pkg:deb/ubuntu/netty?arch=source&distro=esm-apps-legacy%2Fxenial

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1:3.*

1:3.2.6.Final-2

1:4.*

1:4.0.32-1

1:4.0.33-1

1:4.0.34-1

1:4.0.34-1ubuntu0.1~esm1

1:4.0.34-1ubuntu0.1~esm2

1:4.0.34-1ubuntu0.1~esm3

1:4.0.34-1ubuntu0.1~esm4

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1:4.0.34-1ubuntu0.1~esm4",
            "binary_name": "libnetty-java"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55851.json"

Ubuntu:Pro:18.04:LTS

netty

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1:4.*

1:4.1.7-4

1:4.1.7-4ubuntu0.1~esm1

1:4.1.7-4ubuntu0.1

1:4.1.7-4ubuntu0.1+esm1

1:4.1.7-4ubuntu0.1+esm2

1:4.1.7-4ubuntu0.1+esm3

1:4.1.7-4ubuntu0.1+esm4

1:4.1.7-4ubuntu0.1+esm5

1:4.1.7-4ubuntu0.1+esm6

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1:4.1.7-4ubuntu0.1+esm6",
            "binary_name": "libnetty-java"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55851.json"

Ubuntu:Pro:20.04:LTS

netty

Package

Name: netty
Purl: pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Ffocal

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1:4.*

1:4.1.33-1

1:4.1.33-2

1:4.1.33-3

1:4.1.45-1

1:4.1.45-1ubuntu0.1~esm1

1:4.1.45-1ubuntu0.1~esm2

1:4.1.45-1ubuntu0.1~esm3

1:4.1.45-1ubuntu0.1~esm4

1:4.1.45-1ubuntu0.1~esm6

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1:4.1.45-1ubuntu0.1~esm6",
            "binary_name": "libnetty-java"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55851.json"

Ubuntu:Pro:22.04:LTS

netty

Package

Name: netty
Purl: pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fjammy

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1:4.*

1:4.1.48-4

1:4.1.48-4+deb11u1build0.22.04.1

1:4.1.48-4+deb11u2build0.22.04.1

1:4.1.48-4+deb11u2ubuntu0.1~esm1

1:4.1.48-4+deb11u2ubuntu0.1~esm2

1:4.1.48-4+deb11u2ubuntu0.1

1:4.1.48-4+deb11u2ubuntu0.1+esm1

1:4.1.48-4+deb11u2ubuntu0.1+esm3

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1:4.1.48-4+deb11u2ubuntu0.1+esm3",
            "binary_name": "libnetty-java"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55851.json"

Ubuntu:Pro:24.04:LTS

netty

Package

Name: netty
Purl: pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fnoble

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1:4.*

1:4.1.48-7

1:4.1.48-8

1:4.1.48-9

1:4.1.48-9ubuntu0.1~esm1

1:4.1.48-9ubuntu0.1~esm2

1:4.1.48-9ubuntu0.1

1:4.1.48-9ubuntu0.1+esm1

1:4.1.48-9ubuntu0.1+esm3

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1:4.1.48-9ubuntu0.1+esm3",
            "binary_name": "libnetty-java"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55851.json"

Ubuntu:Pro:26.04:LTS

netty

Package

Name: netty
Purl: pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fresolute

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1:4.*

1:4.1.48-10

1:4.1.48-11

1:4.1.48-12

1:4.1.48-13

1:4.1.48-14

1:4.1.48-16

1:4.1.48-16ubuntu0.1~esm2

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1:4.1.48-16ubuntu0.1~esm2",
            "binary_name": "libnetty-buffer-java"
        },
        {
            "binary_version": "1:4.1.48-16ubuntu0.1~esm2",
            "binary_name": "libnetty-common-java"
        },
        {
            "binary_version": "1:4.1.48-16ubuntu0.1~esm2",
            "binary_name": "libnetty-java"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55851.json"