UBUNTU-CVE-2026-75596

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Source

https://ubuntu.com/security/CVE-2026-75596

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-75596.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-75596

Upstream

CVE-2026-75596

Published

2026-08-21T00:00:00Z

Modified

2026-08-21T10:00:22.414358495Z

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 an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, the default io.netty.handler.ssl.SniHandler constructors use the pre-handshake ClientHello aggregation path in handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java at io.netty.handler.ssl.SslClientHelloHandler#decode, where handshakeBuffer.clear() and writeBytes() recopy all previously received body bytes for every additional TLS record. An unauthenticated remote peer can advertise a large ClientHello and deliver its body in thousands of tiny records, causing quadratic CPU work on the event loop before the TLS handshake completes and degrading TLS handling for other clients. This issue is fixed in versions 4.1.137.Final and 4.2.17.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-2026-75596.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

1:4.0.34-1ubuntu0.1~esm5

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1:4.0.34-1ubuntu0.1~esm5",
            "binary_name": "libnetty-java"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-75596.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

1:4.1.7-4ubuntu0.1+esm7

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1:4.1.7-4ubuntu0.1+esm7",
            "binary_name": "libnetty-java"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-75596.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

1:4.1.45-1ubuntu0.1~esm7

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1:4.1.45-1ubuntu0.1~esm7",
            "binary_name": "libnetty-java"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-75596.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

1:4.1.48-4+deb11u2ubuntu0.2

1:4.1.48-4+deb11u2ubuntu0.2+esm1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1:4.1.48-4+deb11u2ubuntu0.2+esm1",
            "binary_name": "libnetty-java"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-75596.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

1:4.1.48-9ubuntu0.2

1:4.1.48-9ubuntu0.2+esm1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1:4.1.48-9ubuntu0.2+esm1",
            "binary_name": "libnetty-java"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-75596.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-2026-75596.json"