CVE-2026-44894 is a high-severity security vulnerability in io.netty:netty-codec-classes-quic (maven), affecting versions >= 4.2.0.Final, <= 4.2.14.Final. It is fixed in 4.2.15.Final.
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.
CVE-2026-44894 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (4.2.15.Final). Upgrading removes the vulnerable code path.
maven
io.netty:netty-codec-classes-quic (>= 4.2.0.Final, <= 4.2.14.Final)io.netty:netty-codec-classes-quic → 4.2.15.Final (maven)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.
Kodem's runtime-powered SCA identifies whether CVE-2026-44894 is reachable in your applications. Explore open-source security for your team.
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Upgrade io.netty:netty-codec-classes-quic to 4.2.15.Final or later to resolve this vulnerability.
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
CVE-2026-44894 is a high-severity security vulnerability in io.netty:netty-codec-classes-quic (maven), affecting versions >= 4.2.0.Final, <= 4.2.14.Final. It is fixed in 4.2.15.Final.
CVE-2026-44894 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
io.netty:netty-codec-classes-quic (maven) versions >= 4.2.0.Final, <= 4.2.14.Final is affected.
Yes. CVE-2026-44894 is fixed in 4.2.15.Final. Upgrade to this version or later.
Whether CVE-2026-44894 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
Upgrade io.netty:netty-codec-classes-quic to 4.2.15.Final or later.