CVE-2026-42585

FAUCET Score

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty incorrectly parses malformed Transfer-Encoding, enabling request smuggling attacks. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

First published: May 13, 2026Last modified: May 13, 2026

Impacted Technologies

Vendor	Product	Version(s)	CPE
		< 4.1.133CPE matchmatch criteria	cpe:2.3:a:netty:netty::::::::
		>= 4.2.0, < 4.2.13CPE matchmatch criteria	cpe:2.3:a:netty:netty::::::::

CVSS Data

CVSS version used by this source: 3.1

6.5MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

LOW

Integrity Impact

LOW

Availability Impact

NONE

Exploitability Score

3.9

Impact Score

2.5

CvssVersion

3.1

Exploit Intelligence

EPSS Score

0.25%

Probability of exploitation in next 30 days

EPSS Percentile

16.2%

Percentile rank of EPSS score among Peer Group

As of 2026-07-27

Model: v2026.06.15

This CVE's current EPSS score of 0.0025 is in the 2nd percentile among its peer group of 51,551 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (9)

mavenpatch availablevia ghsa

Product: io.netty:netty-codec-httpFixed in: 4.2.13.Final

mavenpatch availablevia ghsa

Product: io.netty:netty-codec-httpFixed in: 4.1.133.Final