CriticalFix available
netty — security advisory
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's DNS codec does not enforce RFC 1035 domain name constraints during either encoding or decoding. This creates a bidirectional attack surface: malicious DNS responses can exploit the decoder, and user-influenced hostnames can exploit the encoder. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
- Products
- netty
- Affected versions
- 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, 1:4.1.48-10, 1:4.1.48-10ubuntu0.25.10.1, 1:4.1.48-10ubuntu0.25.10.2, 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, 1:4.1.48-16ubuntu1, 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, 1:4.1.48-4+deb11u2ubuntu0.1+esm1, 1:4.1.48-4+deb11u2ubuntu0.1~esm1, 1:4.1.48-4+deb11u2ubuntu0.1~esm2, 1:4.1.48-7, 1:4.1.48-8, 1:4.1.48-9, 1:4.1.48-9ubuntu0.1, 1:4.1.48-9ubuntu0.1+esm1, 1:4.1.48-9ubuntu0.1~esm1, 1:4.1.48-9ubuntu0.1~esm2
- Fixed versions
- 1:4.1.45-1ubuntu0.1~esm6, 1:4.1.48-16ubuntu0.1~esm2, 1:4.1.48-4+deb11u2ubuntu0.1+esm3, 1:4.1.48-9ubuntu0.1+esm3
- CVEs
- CVE-2026-42579
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:12 UTC · Revision 1
Source evidence
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's DNS codec does not enforce RFC 1035 domain name constraints during either encoding or decoding. This creates a bidirectional attack surface: malicious DNS responses can exploit the decoder, and user-influenced hostnames can exploit the encoder. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
osv:UBUNTU-CVE-2026-42579
netty
Fixed versions: 1:4.1.45-1ubuntu0.1~esm6
netty
Fixed versions: 1:4.1.48-4+deb11u2ubuntu0.1+esm3
netty
Fixed versions: 1:4.1.48-9ubuntu0.1+esm3
netty
Fixed versions: Not specified
netty
Fixed versions: Not specified
netty
Fixed versions: 1:4.1.48-16ubuntu0.1~esm2
Complete source record
{
"id": "794eb9a17e8180e8ac2ba2130a8a83143cbc6ca24dd409d119fc9cc51bc1f219",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-42579",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-42579",
"summary": "Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's DNS codec does not enforce RFC 1035 domain name constraints during either encoding or decoding. This creates a bidirectional attack surface: malicious DNS responses can exploit the decoder, and user-influenced hostnames can exploit the encoder. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.",
"evidence": "osv:UBUNTU-CVE-2026-42579",
"products": [
{
"name": {
"value": "netty",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
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{
"value": "1:4.1.45-1ubuntu0.1~esm6",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "1:4.1.33-1",
"evidence": "/affected/0/versions"
},
{
"value": "1:4.1.33-2",
"evidence": "/affected/0/versions"
},
{
"value": "1:4.1.33-3",
"evidence": "/affected/0/versions"
},
{
"value": "1:4.1.45-1",
"evidence": "/affected/0/versions"
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{
"value": "1:4.1.45-1ubuntu0.1~esm1",
"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
"name": {
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{
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"evidence": "/affected/1/ranges"
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],
"affected_versions": [
{
"value": "1:4.1.48-4",
"evidence": "/affected/1/versions"
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{
"value": "1:4.1.48-4+deb11u1build0.22.04.1",
"evidence": "/affected/1/versions"
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"value": "1:4.1.48-4+deb11u2build0.22.04.1",
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{
"value": "1:4.1.48-4+deb11u2ubuntu0.1~esm2",
"evidence": "/affected/1/versions"
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{
"value": "1:4.1.48-4+deb11u2ubuntu0.1",
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{
"value": "1:4.1.48-4+deb11u2ubuntu0.1+esm1",
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{
"name": {
"value": "netty",
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{
"value": "1:4.1.48-9ubuntu0.1+esm3",
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],
"affected_versions": [
{
"value": "1:4.1.48-7",
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},
{
"value": "1:4.1.48-8",
"evidence": "/affected/2/versions"
},
{
"value": "1:4.1.48-9",
"evidence": "/affected/2/versions"
},
{
"value": "1:4.1.48-9ubuntu0.1~esm1",
"evidence": "/affected/2/versions"
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{
"value": "1:4.1.48-9ubuntu0.1~esm2",
"evidence": "/affected/2/versions"
},
{
"value": "1:4.1.48-9ubuntu0.1",
"evidence": "/affected/2/versions"
},
{
"value": "1:4.1.48-9ubuntu0.1+esm1",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "netty",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1:4.1.48-10",
"evidence": "/affected/3/versions"
},
{
"value": "1:4.1.48-10ubuntu0.25.10.1",
"evidence": "/affected/3/versions"
},
{
"value": "1:4.1.48-10ubuntu0.25.10.2",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "netty",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1:4.1.48-16",
"evidence": "/affected/4/versions"
},
{
"value": "1:4.1.48-16ubuntu1",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "netty",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:4.1.48-16ubuntu0.1~esm2",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": [
{
"value": "1:4.1.48-10",
"evidence": "/affected/5/versions"
},
{
"value": "1:4.1.48-11",
"evidence": "/affected/5/versions"
},
{
"value": "1:4.1.48-12",
"evidence": "/affected/5/versions"
},
{
"value": "1:4.1.48-13",
"evidence": "/affected/5/versions"
},
{
"value": "1:4.1.48-14",
"evidence": "/affected/5/versions"
},
{
"value": "1:4.1.48-16",
"evidence": "/affected/5/versions"
}
]
}
],
"severity": "critical",
"structured": {
"id": "UBUNTU-CVE-2026-42579",
"aliases": [
"UBUNTU-CVE-2026-42579"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:4.1.45-1ubuntu0.1~esm6"
}
]
}
],
"package": {
"name": "netty",
"purl": "pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Ffocal",
"ecosystem": "Ubuntu:Pro:20.04:LTS"
},
"versions": [
"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"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42579.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libnetty-java",
"binary_version": "1:4.1.45-1ubuntu0.1~esm6"
}
],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:4.1.48-4+deb11u2ubuntu0.1+esm3"
}
]
}
],
"package": {
"name": "netty",
"purl": "pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fjammy",
"ecosystem": "Ubuntu:Pro:22.04:LTS"
},
"versions": [
"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"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42579.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libnetty-java",
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],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
},
{
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{
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{
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{
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}
]
}
],
"package": {
"name": "netty",
"purl": "pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fnoble",
"ecosystem": "Ubuntu:Pro:24.04:LTS"
},
"versions": [
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"1:4.1.48-8",
"1:4.1.48-9",
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},
{
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"package": {
"name": "netty",
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"versions": [
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],
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"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42579.json"
},
"ecosystem_specific": {
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{
"binary_name": "libnetty-buffer-java",
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},
{
"binary_name": "libnetty-common-java",
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{
"binary_name": "libnetty-java",
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{
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],
"package": {
"name": "netty",
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"ecosystem": "Ubuntu:Pro:26.04:LTS"
},
"versions": [
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"1:4.1.48-12",
"1:4.1.48-13",
"1:4.1.48-14",
"1:4.1.48-16"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42579.json"
},
"ecosystem_specific": {
"binaries": [
{
"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",
"binary_version": "1:4.1.48-16ubuntu0.1~esm2"
}
],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
}
],
"modified": "2026-10-17T12:58:16.230073268Z",
"provider": "osv",
"upstream": [
"CVE-2026-42579"
],
"references": [
"https://ubuntu.com/security/CVE-2026-42579",
"https://www.cve.org/CVERecord?id=CVE-2026-42579",
"https://github.com/netty/netty/security/advisories/GHSA-cm33-6792-r9fm",
"https://ubuntu.com/security/notices/USN-8401-1"
]
},
"related_cves": [
{
"value": "CVE-2026-42579",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/2/score"
},
"source_id": "core-osv",
"document_id": 358484,
"published_at": "2026-05-13T19:17:00+00:00"
}