CVE-2026-42581

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpObjectDecoder strips a conflicting Content-Length header when a request carries both Transfer-Encoding: chunked and Content-Length, but only for HTTP/1.1 messages. The guard is absent for HTTP/1.0. An attacker that sends an HTTP/1.0 request with both headers causes Netty to decode the body as chunked while leaving Content-Length intact in the forwarded HttpMessage. Any downstream proxy or handler that trusts Content-Length over Transfer-Encoding will disagree on message boundaries, enabling request smuggling. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*

History

21 Jul 2026, 12:18

Type Values Removed Values Added
References
  • () https://access.redhat.com/errata/RHSA-2026:42644 -

10 Jul 2026, 12:16

Type Values Removed Values Added
References
  • () https://access.redhat.com/errata/RHSA-2026:37390 -

09 Jul 2026, 13:17

Type Values Removed Values Added
References
  • () https://access.redhat.com/errata/RHSA-2026:36820 -

30 Jun 2026, 03:19

Type Values Removed Values Added
References
  • () https://access.redhat.com/errata/RHSA-2026:23808 -
  • () https://access.redhat.com/errata/RHSA-2026:24502 -
  • () https://access.redhat.com/errata/RHSA-2026:25123 -
  • () https://access.redhat.com/errata/RHSA-2026:28010 -
  • () https://access.redhat.com/security/cve/CVE-2026-42581 -
  • () https://bugzilla.redhat.com/show_bug.cgi?id=2477232 -
  • () https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42581.json -

17 Jun 2026, 10:48

Type Values Removed Values Added
References () https://github.com/netty/netty/security/advisories/GHSA-xxqh-mfjm-7mv9 - Exploit, Vendor Advisory, Mitigation () https://github.com/netty/netty/security/advisories/GHSA-xxqh-mfjm-7mv9 - Exploit, Mitigation, Vendor Advisory

18 May 2026, 13:14

Type Values Removed Values Added
References () https://github.com/netty/netty/security/advisories/GHSA-xxqh-mfjm-7mv9 - () https://github.com/netty/netty/security/advisories/GHSA-xxqh-mfjm-7mv9 - Exploit, Vendor Advisory, Mitigation
CPE cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
First Time Netty netty
Netty

13 May 2026, 19:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-05-13 19:17

Updated : 2026-07-21 12:18


NVD link : CVE-2026-42581

Mitre link : CVE-2026-42581

CVE.ORG link : CVE-2026-42581


JSON object : View

Products Affected

netty

  • netty
CWE
CWE-444

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')