Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, Netty's HTTP/2-to-HTTP/1.x translation layer (Http2StreamFrameToHttpObjectCodec and InboundHttp2ToHttpAdapter) fails to deduplicate or validate Host headers when an HTTP/2 client supplies both the :authority pseudo-header and a literal host header in a single HEADERS frame. The translator maps :authority to Host and separately copies the literal host header, producing an HttpRequest object containing two Host headers with attacker-controlled differing values. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-444"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59900.json"
}{
"extracted_events": [
{
"cpe": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "4.1.136"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "4.2.0"
},
{
"fixed": "4.2.16"
}
],
"source": "CPE_RANGE"
},
{
"original_tag": "netty-4.1.136.Final",
"range": [
{
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}
],
"source": "REFERENCES_TAG"
},
{
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"range": [
{
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}
],
"source": "REFERENCES_TAG"
}
]
}