Information disclosure in Netty - CVE-2026-50009
Published: June 8, 2026
Vulnerability identifier: #VU133458
CSH Severity: Medium
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-50009
CWE-ID: CWE-200
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to exposure of sensitive information in QUIC stateless reset token generation when observing header-visible connection IDs during source connection ID rotation. A remote attacker can send a spoofed stateless reset packet to cause a denial of service.
The issue occurs when the default HMAC-based connection-ID and stateless-reset-token generators use the same JVM-wide static key, allowing an on-path observer to derive the reset token from QUIC headers without decrypting payload data.
Affected software
Netty
How to mitigate CVE-2026-50009
Install security update from vendor's website.
Netty - update to 4.2.15