Netty: HTTP/1.0 TE+CL Coexistence Bypasses Smuggling Sanitization
Summary
| CVE | CVE-2026-42581 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-13 19:17:23 UTC |
| Updated | 2026-07-21 12:18:38 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 9.8 CRITICAL from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.000170000 probability, percentile 0.045490000 (date 2026-05-25)
Problem Types: CWE-444 | CWE-444 CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') | CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | ADP | CVSS | 7.2 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
| 3.1 | [email protected] | Secondary | 5.8 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 7.2 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
| 3.1 | CNA | DECLARED | 5.8 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Netty | Netty | affected >= 4.2.0.Alpha1, < 4.2.13.Final | Not specified |
| CNA | Netty | Netty | affected < 4.1.133.Final | Not specified |
| ADP | Red Hat | Cryostat 4 On RHEL 9 | unaffected 4.2.0-10 * rpm | Not specified |
| ADP | Red Hat | Cryostat 4 On RHEL 9 | unaffected 4.2.0-10 * rpm | Not specified |
| ADP | Red Hat | Cryostat 4 On RHEL 9 | unaffected 4.2.0-10 * rpm | Not specified |
| ADP | Red Hat | Red Hat Build Of Apache Camel 4.18.1.P1 For Spring Boot 3.5.16 | unaffected codec-http * rpm | Not specified |
| ADP | Red Hat | Red Hat Build Of Quarkus 3.27.4 | unaffected codec-http * rpm | Not specified |
| ADP | Red Hat | Red Hat Build Of Quarkus 3.33.2 | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI 2.25 | unaffected 1783443816 * rpm | Not specified |
| ADP | Red Hat | Red Hat OpenShift Dev Spaces 3.28 | unaffected 1780948325 * rpm | Not specified |
| ADP | Red Hat | Red Hat OpenShift Dev Spaces 3.28 | unaffected 1780696380 * rpm | Not specified |
| ADP | Red Hat | Red Hat OpenShift Dev Spaces 3.28 | unaffected 1780694994 * rpm | Not specified |
| ADP | Red Hat | Red Hat OpenShift Dev Spaces 3.29 | unaffected 1782989027 * rpm | Not specified |
| ADP | Red Hat | OpenShift Serverless | Not specified | Not specified |
| ADP | Red Hat | OpenShift Serverless | Not specified | Not specified |
| ADP | Red Hat | OpenShift Serverless | Not specified | Not specified |
| ADP | Red Hat | OpenShift Serverless | Not specified | Not specified |
| ADP | Red Hat | OpenShift Serverless | Not specified | Not specified |
| ADP | Red Hat | OpenShift Serverless | Not specified | Not specified |
| ADP | Red Hat | OpenShift Serverless | Not specified | Not specified |
| ADP | Red Hat | OpenShift Serverless | Not specified | Not specified |
| ADP | Red Hat | OpenShift Serverless | Not specified | Not specified |
| ADP | Red Hat | OpenShift Serverless | Not specified | Not specified |
| ADP | Red Hat | Red Hat AMQ Broker 7 | Not specified | Not specified |
| ADP | Red Hat | Red Hat AMQ Clients | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of Apache Camel 4 For Quarkus 3 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of Apicurio Registry 2 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of Apicurio Registry 3 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of Debezium 3 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of Keycloak | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of Keycloak | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of Keycloak | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of Keycloak | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of Keycloak | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of OptaPlanner 8 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Data Grid 8 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux AI RHEL AI 3 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux AI RHEL AI 3 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux AI RHEL AI 3 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Fuse 7 | Not specified | Not specified |
| ADP | Red Hat | Red Hat JBoss Enterprise Application Platform 7 | Not specified | Not specified |
| ADP | Red Hat | Red Hat JBoss Enterprise Application Platform 8 | Not specified | Not specified |
| ADP | Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI RHOAI | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI RHOAI | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI RHOAI | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI RHOAI | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI RHOAI | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI RHOAI | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI RHOAI | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI RHOAI | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI RHOAI | Not specified | Not specified |
| ADP | Red Hat | Red Hat Process Automation 7 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Satellite 6 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Satellite 6 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Single Sign-On 7 | Not specified | Not specified |
| ADP | Red Hat | Streams For Apache Kafka 2 | Not specified | Not specified |
| ADP | Red Hat | Streams For Apache Kafka 3 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/netty/netty/security/advisories/GHSA-xxqh-mfjm-7mv9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | Exploit, Mitigation, Vendor Advisory |
| access.redhat.com/security/cve/CVE-2026-42581 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:23808 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42581.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:42644 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:37390 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:25123 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | |
| access.redhat.com/errata/RHSA-2026:36820 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:28010 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:24502 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-05-13T19:02:26.404Z | Reported to Red Hat. |
| ADP | 2026-05-13T17:54:44.492Z | Made public. |
Solutions
ADP: RHSA-2026:28010: Cryostat 4 on RHEL 9
ADP: RHSA-2026:42644: Red Hat OpenShift AI 2.25
ADP: RHSA-2026:25123: Red Hat OpenShift Dev Spaces 3.28
ADP: RHSA-2026:36820: Red Hat OpenShift Dev Spaces 3.29
ADP: RHSA-2026:37390: Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16
ADP: RHSA-2026:23808: Red Hat build of Quarkus 3.27.4
ADP: RHSA-2026:24502: Red Hat build of Quarkus 3.33.2
Workarounds
ADP: To mitigate this issue, configure any reverse proxies or load balancers in front of Netty to either reject HTTP/1.0 requests containing both Transfer-Encoding: chunked and Content-Length headers, or to explicitly prioritize the Transfer-Encoding header over Content-Length for HTTP/1.0 traffic. This ensures consistent interpretation of message boundaries and prevents request smuggling attacks.
There are currently no legacy QID mappings associated with this CVE.