CVE-2026-44894: Netty codec classes quic Netty's Default QUIC Token Handler Vulnerability
HIGHCVE-2026-44894 is a HIGH (CVSS 7.5) netty's default quic token handler vulnerability (CWE-940: Improper Verification of Source of a Communication Channel) affecting Netty codec classes quic libraries in the Maven ecosystem. The issue involves netty's default quic token handler accepts any client-supplied token. Remediation is available by upgrading affected packages to version 4.2.15.Final.
CVE-2026-44894 at a Glance
Security Impact
CVSS: 7.5
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N).
How to Fix CVE-2026-44894
To remediate this vulnerability, upgrade all affected Netty codec classes quic dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-codec-classes-quic</artifactId>
<version>4.2.15.Final</version>
</dependency>Run the following command in your project directory to verify that all resolved dependencies use the patched release:
mvn dependency:tree -Dincludes=io.nettyHow to Check if You Are Affected
To determine whether your Java application is affected by CVE-2026-44894, inspect your build dependencies using the Maven Dependency Plugin:
mvn dependency:tree -Dincludes=io.nettyAnalyze the terminal output to locate any version of Netty codec classes quic in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.2.15.Final), your application is affected.
Note: The mvn dependency:tree -Dincludes=io.netty command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-940: Improper Verification of Source of a Communication Channel, where the product establishes a communication channel to handle an incoming request that has been initiated by an actor, but it does not properly verify that the request is coming from the expected origin. In Netty codec classes quic, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-44894 Affected Netty codec classes quic Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
io.netty:netty-codec-classes-quic
|
Maven |
≥ 4.2.0.Final
< 4.2.15.Final
|
4.2.15.Final
|
References
Frequently Asked Questions
What is CVE-2026-44894?
Which Netty codec classes quic versions are affected?
What version fixes CVE-2026-44894?
Is netty-codec-classes-quic affected?
What is the CVSS score of CVE-2026-44894?
What CWE is associated with CVE-2026-44894?
How can I check Maven dependencies for CVE-2026-44894?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-cmm3-54f8-px4j",
"modified" : "2026-06-12T19:29:17Z",
"published" : "2026-06-08T22:59:43Z",
"aliases" : [ "CVE-2026-44894" ],
"summary" : "Netty's Default QUIC token handler accepts any client-supplied token",
"details" : "NoQuicTokenHandler is the tokenHandler used when the application does not set one. Its writeToken() returns false (server will not send Retry — acceptable), but validateToken() unconditionally `return 0`. In QuicheQuicServerCodec.handlePacket(), a non-negative return from validateToken() is interpreted as 'token is valid, ODCID starts at offset 0', causing the server to call quiche_accept as if the client's address had been validated by a Retry round-trip. Per RFC 9000 §8.1, a validated address lifts the 3× anti-amplification send limit. Thus any attacker who includes ANY non-empty token bytes in an Initial packet — with a spoofed victim source IP — causes the Netty server to treat the victim as validated and reflect full-size handshake flights (certificates, etc.) toward it without the 3× cap. The correct 'no token handler' semantics would be to return -1 (invalid) so the normal un-validated path and amplification limit apply.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Maven",
"name" : "io.netty:netty-codec-classes-quic"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "4.2.0.Final"
}, {
"fixed" : "4.2.15.Final"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 4.2.14.Final"
}
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/netty/netty/security/advisories/GHSA-cmm3-54f8-px4j"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-44894"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/netty/netty"
}, {
"type" : "WEB",
"url" : "https://github.com/netty/netty/releases/tag/netty-4.2.15.Final"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-940" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-06-08T22:59:43Z",
"nvd_published_at" : "2026-06-12T15:16:26Z"
}
}