{
"id": "GHSA-4qhr-g3c6-fcfx",
"aliases": [
"CVE-2026-56817"
],
"details": "Any caller that can deliver bytes to a Netty channel pipeline containing `XmlDecoder` can send XML with a DOCTYPE declaration to a parser instantiated with no security configuration — but whether external entities are actually resolved depends on Aalto XML's async parser behavior, making this a confirmed misconfiguration with conditional exploitability.",
"summary": "Netty XML: Injection / Risky Sink — unconfigured XML factory with active DTD and entity handling",
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "4.2.0.Final"
},
{
"fixed": "4.2.16.Final"
}
]
}
],
"package": {
"name": "io.netty:netty-codec-xml",
"ecosystem": "Maven"
},
"database_specific": {
"last_known_affected_version_range": "<= 4.2.15.Final"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "4.1.0.Final"
},
{
"fixed": "4.1.136.Final"
}
]
}
],
"package": {
"name": "io.netty:netty-codec-xml",
"ecosystem": "Maven"
},
"database_specific": {
"last_known_affected_version_range": "<= 4.1.135.Final"
}
}
],
"modified": "2026-07-22T21:43:17Z",
"severity": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N"
}
],
"published": "2026-07-22T21:43:16Z",
"references": [
{
"url": "https://github.com/netty/netty/security/advisories/GHSA-4qhr-g3c6-fcfx",
"type": "WEB"
},
{
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56817",
"type": "ADVISORY"
},
{
"url": "https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b",
"type": "WEB"
},
{
"url": "https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6",
"type": "WEB"
},
{
"url": "https://github.com/netty/netty",
"type": "PACKAGE"
},
{
"url": "https://github.com/netty/netty/releases/tag/netty-4.1.136.Final",
"type": "WEB"
},
{
"url": "https://github.com/netty/netty/releases/tag/netty-4.2.16.Final",
"type": "WEB"
}
],
"schema_version": "1.4.0",
"database_specific": {
"cwe_ids": [
"CWE-611"
],
"severity": "HIGH",
"github_reviewed": true,
"nvd_published_at": "2026-07-21T23:17:52Z",
"github_reviewed_at": "2026-07-22T21:43:16Z"
}
}