CVE-2026-44894
Published: 12 June 2026
Summary
CVE-2026-44894 is a high-severity Improper Verification of Source of a Communication Channel (CWE-940) vulnerability in Netty Netty. Its CVSS base score is 7.5 (High).
Operationally, ranked at the 13.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-36435
Vulnerability details
Netty is a network application framework for development of protocol servers and clients. NoQuicTokenHandler is the tokenHandler used when the application does not set one. Prior to version 4.2.15.Final, its writeToken() returns false (server will not send Retry — acceptable),…
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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. Version 4.2.15.Final patches the issue.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Enforces verification of the source of a communication channel by requiring identification and authentication of services first.
Requires explicit verification of the source and integrity of the channel used for authentication and other security functions.
Provides the means to verify the source of name-resolution responses instead of relying on unauthenticated channels.
Requires explicit verification of the communication source, blocking session hijacking via spoofed or alternate channels.