Home/CVE/Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.129.Final and 4.2.8.Final
CVE

CVE-2025-67735

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.129.Final and 4.2.8.Final

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.129.Final and 4.2.8.Final, the io.netty.handler.codec.http.HttpRequestEncoder has a CRLF injection with the request URI when constructing a request. This leads to request smuggling when HttpRequestEncoder is used without proper sanitization of the URI.

Any application / framework using HttpRequestEncoder can be subject to be abused to perform request smuggling using CRLF injection. Versions 4.1.129.Final and 4.2.8.Final fix the issue.

MEDIUM · CVSS 6.5 EPSS 0.00024
Schedule remediation
  • Public exploit or PoC is available
  • SSVC automatable: yes - attacks can be scripted at scale
Sigma rules0 YARA rules0

Affected Products & Versions

2
netty< 4.1.129
netty>= 4.2.0 and < 4.2.8

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
Maven io.netty:netty-codec-http MODERATE fixed in 4.2.8.Final

Public Exploits & PoCs

1

Scoring & Timeline

6.5
MEDIUM · CVSS v3.1 · security-advisories@github.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD16 Dec 2025 · 01:15 AM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
SSVC triage · cisa-vulnrichment
Exploitation
poc
Automatable
yes
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.

Vendor Advisories

5
rhsaRHSA-2026:1899Moderate
rhsaRHSA-2026:1965Moderate
suse-csafSUSE-SU-2025:4489-1
suse-csafopenSUSE-SU-2025:15824-1
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