CVE-2026-50009: Netty QUIC Stateless Reset Token Material Vulnerability
MODERATECVE-2026-50009 is a MODERATE (CVSS 4.8) quic stateless reset token material vulnerability (CWE-330: Use of Insufficiently Random Values) affecting Netty libraries in the Maven ecosystem. The issue involves quic stateless reset token material exposed through header-visible connection ids. Remediation is available by upgrading affected packages to version 4.2.15.Final.
CVE-2026-50009 at a Glance
Security Impact
CVSS: 4.8
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L).
How to Fix CVE-2026-50009
To remediate this vulnerability, upgrade all affected Netty 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-2026-50009, inspect your build dependencies using the Maven Dependency Plugin:
mvn dependency:tree -Dincludes=io.nettyAnalyze the terminal output to locate any version of Netty 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-330: Use of Insufficiently Random Values, where the product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers. In Netty, 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-2026-50009 Affected Netty 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-2026-50009?
Which Netty versions are affected?
What version fixes CVE-2026-50009?
Is netty-codec-classes-quic affected?
What is the CVSS score of CVE-2026-50009?
What CWE is associated with CVE-2026-50009?
How can I check Maven dependencies for CVE-2026-50009?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-cq4q-cv5g-r8q5",
"modified" : "2026-06-15T20:44:20Z",
"published" : "2026-06-15T20:44:20Z",
"aliases" : [ "CVE-2026-50009" ],
"summary" : "Netty: QUIC stateless reset token material exposed through header-visible connection IDs",
"details" : "### Summary\nNetty QUIC exposes the stateless reset token on the network path when using the default HMAC-based connection-ID and stateless-reset-token generators. The reset token for the server's current source connection ID can be derived from bytes that appear as the connection ID in QUIC headers after a source-CID rotation. An on-path attacker observing the headers can use the token to perform a Denial of Service by sending a spoofed Stateless Reset packet.\n\n### Details\nThe sign-based connection ID generator (HmacSignQuicConnectionIdGenerator) and reset token generator (HmacSignQuicResetTokenGenerator) both evaluate HMAC-SHA256 with the same JVM-wide static key (io.netty.handler.codec.quic.Hmac).\n\nDuring source CID rotation (QuicheQuicChannel.newSourceConnectionIds), the current server source CID C is used as input to produce the next CID N. The stateless reset token for C is defined over HMAC(K, C), specifically the first 16 bytes. The next CID N is the first L bytes of the same digest, where L = |C|.\n\nWhenever L ≥ 16, the first 16 bytes of N are exactly the stateless reset token for C. Because N is carried in QUIC headers as a connection ID, an observer can read the headers and learn the reset token without decrypting the payload.\n\nThis directly violates RFC 9000\nhttps://datatracker.ietf.org/doc/html/rfc9000#name-calculating-a-stateless-res: `The stateless reset token MUST be difficult to guess.`\nAdditionally https://datatracker.ietf.org/doc/html/rfc9000#name-stateless-reset-oracle\n\n### Impact\nInformation Disclosure and Denial of Service. An on-path attacker can obtain the stateless reset token from the connection ID header and attempt to abruptly close the client side of the connection by sending a spoofed Stateless Reset datagram.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L"
} ],
"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-cq4q-cv5g-r8q5"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-50009"
}, {
"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-200", "CWE-330" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-06-15T20:44:20Z",
"nvd_published_at" : "2026-06-12T16:16:31Z"
}
}