Description
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.
Affected products
netty: netty
References10
- github.com/netty/netty/security/advisories/GHSA-xxqh-mfjm-7mv9 ExploitMitigationVendor Advisory
- github.com/netty/netty/security/advisories/GHSA-xxqh-mfjm-7mv9 ExploitMitigationVendor Advisory
- access.redhat.com/errata/RHSA-2026:23808
- access.redhat.com/errata/RHSA-2026:24502
- access.redhat.com/errata/RHSA-2026:25123
- access.redhat.com/errata/RHSA-2026:28010
- access.redhat.com/errata/RHSA-2026:36820
- access.redhat.com/errata/RHSA-2026:37390
- access.redhat.com/errata/RHSA-2026:42644
- access.redhat.com/errata/RHSA-2026:49700
Metrics
- CVSS 3.1
-
9.8
CRITICAL
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 51 · as of 14 November 2026
- CWE
- CWE-444
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