Netty is a network application framework for development of protocol servers and clients
Description
Netty is a network application framework for development of protocol servers and clients
AI Analyst Comment
Remediation
Apply vendor security updates immediately. Monitor for exploitation attempts and review access logs.
---METADATA---
VENDOR: Netty
PRODUCT: Netty
AFFECTED_VERSIONS: io.netty:netty-codec-haproxy versions >= 4.2.0.Final, <= 4.2.14.Final and <= 4.1.134.Final
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Description Summary:
A memory leak in the Netty HAProxy PROXY protocol v2 codec allows unauthenticated remote attackers to cause a denial of service via specifically crafted nested TLV headers.
Executive Summary:
A memory leak vulnerability in Netty's HAProxy PROXY protocol codec poses a significant risk of service disruption due to resource exhaustion.
Vulnerability Details
CVE-ID: CVE-2026-48059
Affected Software: Netty
Affected Versions: io.netty:netty-codec-haproxy versions >= 4.2.0.Final, <= 4.2.14.Final and <= 4.1.134.Final
Vulnerability: This vulnerability involves a failure to release ByteBuf memory when processing nested PP2_TYPE_SSL TLVs at depth two or greater. This allows an unauthenticated attacker to trigger progressive memory consumption, leading to system instability.
Business Impact
With a CVSS score of 7.5 (High), this vulnerability presents a substantial risk to application availability. Successful exploitation results in memory exhaustion, effectively causing a denial-of-service condition that can crash critical network services, leading to potential operational downtime and loss of service continuity.
Remediation Plan
Immediate Action: Upgrade to Netty versions 4.1.135.Final or 4.2.15.Final immediately to resolve the memory leak.
Proactive Monitoring: Monitor server memory utilization and garbage collection metrics for unusual spikes that correlate with incoming network connections.
Compensating Controls: Implement rate limiting or ingress filtering on network traffic to identify and drop malformed or excessively nested HAProxy PROXY protocol headers before they reach the application layer.
Exploitation Status
Public Exploit Available: false
Analyst Notes: As of June 15, 2026, there is no public information indicating active exploitation of this vulnerability. However, due to the nature of the flaw, the potential for exploitation is high.
Analyst Recommendation
The vulnerability represents a clear path to denial-of-service for any infrastructure relying on Netty's HAProxy codec. Organizations should prioritize updating to the patched versions (4.1.135.Final or 4.2.15.Final) across all affected environments to prevent service degradation.