VulnerabilityAnalyzed

CVE-2026-50009

Prior to version 4.2.15.Final, Netty QUIC exposes the stateless reset token on the network path when using the default HMAC-based connection-ID and stateless-reset-token generators.

MEDIUM 4.8EPSS 0.20%

Does this matter?

Lower severity and a low EPSS score (0.20%). Track it; it rarely justifies an emergency change on its own.

Description

Netty is a network application framework for development of protocol servers and clients. Prior to version 4.2.15.Final, Netty 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. Version 4.2.15.Final patches the issue.

CVSS 3.1: 4.8 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
EPSS: 0.20% probability · 10th percentile
CISA KEV: Not listed
Weakness: CWE-200, CWE-330
Affected: netty/netty
Source: security-advisories@github.com

References

https://github.com/netty/netty/releases/tag/netty-4.2.15.FinalRelease Notes
https://github.com/netty/netty/security/advisories/GHSA-cq4q-cv5g-r8q5Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.