Netty's HTTP/3 codec (io.netty:netty-codec-http3) in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the… (CVE-2026-100659)
Netty's HTTP/3 codec versions 4.2.0.Final through 4.2.17.Final do not enforce the RFC 9114 requirement that the :authority pseudo-header and the literal host header, when both present, must have the same value. This allows a remote unauthenticated attacker to send a HEADERS frame with conflicting authority values, potentially bypassing routing, virtual-host, and access-control decisions. The issue is fixed in version 4.2.18.Final.
AI Analysis
Technical Summary
The vulnerability in Netty's HTTP/3 codec (io.netty:netty-codec-http3) affects versions 4.2.0.Final through 4.2.17.Final. It arises because the codec does not enforce the RFC 9114 requirement that the :authority pseudo-header and the literal host header field, when both are present, must carry the same value. An attacker can send a single HEADERS frame with differing values in these fields, causing the request to be accepted with conflicting authorities. This discrepancy can be exploited to bypass routing, virtual-host, and access-control mechanisms when different components in the request path rely on different header fields. The vulnerability is addressed in version 4.2.18.Final.
Potential Impact
A remote unauthenticated attacker can exploit this vulnerability to bypass routing, virtual-host, and access-control decisions by sending a HEADERS frame with conflicting :authority and host header values. This can lead to unauthorized access or misrouting of HTTP/3 requests. The confidentiality and integrity of the affected system could be partially compromised. There is no impact on availability reported.
Mitigation Recommendations
Upgrade to Netty version 4.2.18.Final or later, where this issue is fixed. No other mitigation is indicated or required according to the available data.
Netty's HTTP/3 codec (io.netty:netty-codec-http3) in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the… (CVE-2026-100659)
Description
Netty's HTTP/3 codec versions 4.2.0.Final through 4.2.17.Final do not enforce the RFC 9114 requirement that the :authority pseudo-header and the literal host header, when both present, must have the same value. This allows a remote unauthenticated attacker to send a HEADERS frame with conflicting authority values, potentially bypassing routing, virtual-host, and access-control decisions. The issue is fixed in version 4.2.18.Final.
CVSS v3.1
Score 6.5medium
Affected software
pkg:maven/io.netty/netty-codec-http3Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Netty's HTTP/3 codec (io.netty:netty-codec-http3) affects versions 4.2.0.Final through 4.2.17.Final. It arises because the codec does not enforce the RFC 9114 requirement that the :authority pseudo-header and the literal host header field, when both are present, must carry the same value. An attacker can send a single HEADERS frame with differing values in these fields, causing the request to be accepted with conflicting authorities. This discrepancy can be exploited to bypass routing, virtual-host, and access-control mechanisms when different components in the request path rely on different header fields. The vulnerability is addressed in version 4.2.18.Final.
Potential Impact
A remote unauthenticated attacker can exploit this vulnerability to bypass routing, virtual-host, and access-control decisions by sending a HEADERS frame with conflicting :authority and host header values. This can lead to unauthorized access or misrouting of HTTP/3 requests. The confidentiality and integrity of the affected system could be partially compromised. There is no impact on availability reported.
Mitigation Recommendations
Upgrade to Netty version 4.2.18.Final or later, where this issue is fixed. No other mitigation is indicated or required according to the available data.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-7j27-hw46-m8m8
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-100659"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6ab89be2f7a7c54106942065
Added to database: 09/27/2026, 04:30:26 UTC
Last enriched: 09/27/2026, 04:44:01 UTC
Last updated: 09/28/2026, 01:47:40 UTC
Views: 19
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