CVE-2026-100664

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Source
https://cve.org/CVERecord?id=CVE-2026-100664
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-100664.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-100664
Aliases
  • GHSA-hfr2-x62w-v49h
Downstream
Published
2026-09-26T13:23:30Z
Modified
2026-09-30T03:30:55Z
Severity
  • 8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
Netty 4.2.2 through 4.2.17 HTTP/1 Host Header Authority Confusion
Details

Netty's HTTP/3 codec (io.netty:netty-codec-http3) versions 4.2.2.Final through 4.2.17.Final builds the HTTP/3 :authority pseudo-header from the HTTP/1 Host header before considering the authority of an absolute-form HTTP/1 request-target. In HttpConversionUtil.toHttp3Headers(HttpMessage, boolean) — reached via Http3FrameToHttpObjectCodec(false) — a non-empty Host header takes precedence over the request-target authority, contrary to the HTTP/1.1 rule that a server receiving an absolute-form request-target must ignore the Host header. In a Netty-based HTTP/1-to-HTTP/3 gateway, proxy, or protocol bridge, a remote client can send a request such as "GET https://trusted.example/admin HTTP/1.1" with "Host: attacker.example", causing components that validate, authorize, or route on the RFC-defined request-target authority to reach a different decision than the upstream HTTP/3 peer, which receives :authority derived from the conflicting Host header. This authority confusion can affect virtual-host routing, allow-list checks, backend selection, cache keys, and URL generation. The advisory reports integrity impact only (no code execution, memory corruption, or availability impact). Fixed in 4.2.18.Final.

Database specific 
{
    "cna_assigner":  "VulnCheck",
    "cwe_ids":  [
        "CWE-20"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100664.json"
}
References

Affected packages

Git / github.com/netty/netty

Affected ranges

Type
GIT
Repo
https://github.com/netty/netty
Events
Introduced
660edeaefad4a4cedbd61584e8f668ad2d89f0b8
Fixed
2521f494432e27415a567d3a81a9eb907abf20b3
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "4.2.2.Final"
        },
        {
            "fixed":  "4.2.18.Final"
        },
        {
            "fixed":  "4.2.17.Final"
        }
    ],
    "source":  [
        "AFFECTED_FIELD",
        "DESCRIPTION"
    ]
}

Affected versions

netty-4.*
netty-4.2.10.Final
netty-4.2.11.Final
netty-4.2.12.Final
netty-4.2.13.Final
netty-4.2.14.Final
netty-4.2.15.Final
netty-4.2.16.Final
netty-4.2.17.Final
netty-4.2.2.Final
netty-4.2.3.Final
netty-4.2.4.Final
netty-4.2.5.Final
netty-4.2.6.Final
netty-4.2.7.Final
netty-4.2.8.Final
netty-4.2.9.Final
Other
netty-clang-bin

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-100664.json"