Netty's Default QUIC token handler accepts any client-supplied token

Summary

CVECVE-2026-44894
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-12 15:16:26 UTC
Updated2026-06-30 03:20:02 UTC
DescriptionNetty 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), 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.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS: 0.001430000 probability, percentile 0.039350000 (date 2026-07-04)

Problem Types: CWE-940 | CWE-346 | CWE-940 CWE-940: Improper Verification of Source of a Communication Channel | CWE-346 Origin Validation Error


VersionSourceTypeScoreSeverityVector
3.1ADPCVSS7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1[email protected]Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
3.10b0ca135-0b70-47e7-9f44-1890c2a1c46cSecondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Netty Netty All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Netty Netty affected >= 4.2.0.Final, < 4.2.15.Final Not specified
ADP Red Hat Red Hat Build Of Apache Camel - HawtIO 4 Not specified Not specified

References

ReferenceSourceLinkTags
github.com/netty/netty/security/advisories/GHSA-cmm3-54f8-px4j [email protected] github.com Vendor Advisory
access.redhat.com/security/cve/CVE-2026-44894 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
bugzilla.redhat.com/show_bug.cgi 0b0ca135-0b70-47e7-9f44-1890c2a1c46c bugzilla.redhat.com
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44894.json 0b0ca135-0b70-47e7-9f44-1890c2a1c46c security.access.redhat.com
github.com/netty/netty/releases/tag/netty-4.2.15.Final [email protected] github.com Release Notes
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

SourceTimeEvent
ADP2026-06-12T15:01:08.840ZReported to Red Hat.
ADP2026-06-12T14:06:54.213ZMade public.

Workarounds

ADP: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

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