Detections
Analytics

Echo: io.netty:netty-codec-haproxy: security update to 4.1.136.Final

high Tenable Cloud Security Plugin ID 459614

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - Netty is a network application framework for development of protocol servers and clients. In versions
 4.2.0.Final up to (but not including) 4.2.16.Final, and 4.1.0.Final up to (but not including) 4.1.135, the
 `HAProxyMessageDecoder` in Netty's `codec-haproxy` module performs protocol version detection by reading
 the 13th byte as a signed Java `byte` and widening it to `int` without masking; a PROXY protocol v2 binary
 prefix followed by version byte `0xFF` sign-extends to `-1`, collides with the decoder's need-more-data
 sentinel, and causes `ByteToMessageDecoder` to accumulate inbound bytes in an unbounded `cumulation`
 buffer until direct memory is exhausted. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
 (CVE-2026-55851)

Solution

Update the io.netty:netty-codec-haproxy library and its related packages to version 4.1.136.Final or later.

See Also

https://advisory.echohq.com/cve/CVE-2026-55851

Plugin Details

Severity: High

ID: 459614

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/3/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.74

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2026-55851

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 8.7

Threat Score: 6.6

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 9/28/2026

Vulnerability Publication Date: 7/21/2026

Reference Information

CVE: CVE-2026-55851