Netty has a CRLF Injection vulnerability in io.netty.handler.codec.http.HttpRequestEncoder
Priority HIGH 68CWE-93Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Partial Red Hat: 2 fixed, 26 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.0032 25th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial netty (netty): 4.2.8.Final, 4.1.129.Finalio.netty:netty-codec-http (Maven): 4.2.8.Final, 4.1.129.FinalRed Hat: 2 advisoriesRed Hat: 2 fixed, 26 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| netty | netty | 4.2.0.Alpha1 to before 4.2.8.Final; before 4.1.129.Final | 4.2.8.Final, 4.1.129.Final | Patch available | CNA |
| — | io.netty:netty-codec-http (Maven) | 4.2.0.Alpha1 to before 4.2.8.Final | 4.2.8.Final | Patch available | GHSA-84h7-rjj3-6jx4 |
| — | io.netty:netty-codec-http (Maven) | before 4.1.129.Final | 4.1.129.Final | Patch available | GHSA-84h7-rjj3-6jx4 |
- netty Vendornetty Affected 4.2.0.Alpha1 to before 4.2.8.Final; before 4.1.129.Final Fixed in 4.2.8.Final, 4.1.129.Final Patch available CNA
- io.netty:netty-codec-http (Maven) Vendor— Affected 4.2.0.Alpha1 to before 4.2.8.Final Fixed in 4.2.8.Final Patch available GHSA-84h7-rjj3-6jx4
- io.netty:netty-codec-http (Maven) Vendor— Affected before 4.1.129.Final Fixed in 4.1.129.Final Patch available GHSA-84h7-rjj3-6jx4
Remediation
- Fix · CNA netty (netty) Fixed in 4.2.8.Final, 4.1.129.Final
- Fix · GHSA-84h7-rjj3-6jx4 io.netty:netty-codec-http (Maven) Fixed in 4.2.8.Final Advisory →
- Fix · GHSA-84h7-rjj3-6jx4 io.netty:netty-codec-http (Maven) Fixed in 4.1.129.Final Advisory →
Red Hat 2 advisories
- RHSA-2026:1965 Released 2026-02-05 · Red Hat rating ModerateRed Hat build of Quarkus 3.27.2 release and security update
- Red Hat build of Quarkus 3.27.2.redhat com.ongres.scram.scram-common-3.2.0.redhat-00001.jar, io.netty.netty-codec-http-4.1.130.Final-redhat-00001.jar, io.quarkus.quarkus-rest-3.27.2.redhat-00001.jar +1
- RHSA-2026:1899 Released 2026-02-05 · Red Hat rating ModerateRed Hat build of Quarkus 3.20.5 release and security update
- Red Hat build of Quarkus 3.20.5.redhat com.ongres.scram.scram-common-3.2.0.redhat-00001.jar, io.netty.netty-codec-http-4.1.130.Final-redhat-00001.jar, io.quarkus.quarkus-rest-3.20.5.redhat-00001.jar
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Cryostat 4 | Affected | No fix yet: Fix deferred |
| Logging Subsystem for Red Hat OpenShift | Affected | No fix yet: Fix deferred |
| OpenShift Serverless | Affected | No fix yet: Fix deferred |
| Red Hat AMQ Broker 7 | Affected | No fix yet: Fix deferred |
| Red Hat AMQ Clients | Affected | No fix yet: Fix deferred |
| Red Hat Data Grid 8 | Affected | No fix yet: Fix deferred |
| Red Hat Fuse 7 | Affected | No fix yet: Fix deferred |
| Red Hat JBoss Enterprise Application Platform 7 | Affected | No fix yet: Fix deferred |
| Red Hat JBoss Enterprise Application Platform 8 | Affected | No fix yet: Fix deferred |
| Red Hat JBoss Enterprise Application Platform Expansion Pack | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift AI (RHOAI) | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Dev Spaces | Affected | No fix yet: Fix deferred |
| Red Hat Process Automation 7 | Affected | No fix yet: Fix deferred |
| Red Hat Satellite 6 | Affected | No fix yet: Fix deferred |
| Red Hat Single Sign-On 7 | Affected | No fix yet: Fix deferred |
| Red Hat build of Apache Camel - HawtIO 4 | Affected | No fix yet: Fix deferred |
| Red Hat build of Apache Camel 4 for Quarkus 3 | Affected | No fix yet: Fix deferred |
| Red Hat build of Apache Camel for Spring Boot 4 | Affected | No fix yet: Fix deferred |
| Red Hat build of Apicurio Registry 2 | Affected | No fix yet: Fix deferred |
| Red Hat build of Apicurio Registry 3 | Affected | No fix yet: Fix deferred |
| Red Hat build of Debezium 2 | Affected | No fix yet: Fix deferred |
| Red Hat build of Debezium 3 | Affected | No fix yet: Fix deferred |
| Red Hat build of OptaPlanner 8 | Affected | No fix yet: Fix deferred |
| Red Hat build of Quarkus | Affected | No fix yet |
| streams for Apache Kafka 2 | Affected | No fix yet: Fix deferred |
| streams for Apache Kafka 3 | Affected | No fix yet: Fix deferred |
| Red Hat build of Quarkus 3.20.5.redhat | Fixed | RHSA-2026:1899 |
| Red Hat build of Quarkus 3.27.2.redhat | Fixed | RHSA-2026:1965 |
Not affected: 2 products
- Red Hat build of Quarkus 3.20.5.redhat
- Red Hat build of Quarkus 3.27.2.redhat
Timeline
- 2026-10-02 Threatist record created from CVE-2025-67735
- 2026-10-03 Alias added: GHSA-84h7-rjj3-6jx4
- 2026-10-20 Fix available: Red Hat build of Quarkus 3.20.5.redhat, Red Hat build of Quarkus 3.27.2.redhat · Red Hat
References
More Netty vulnerabilities
- TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
- TI-2026-30861 Netty: HTTP/1.0 TE+CL Coexistence Bypasses Smuggling Sanitization CVSS 3.1CRITICAL 9.8
- TI-2026-30864 Netty: HttpClientCodec response desynchronization CVSS 3.1CRITICAL 9.1
- TI-2026-30859 Netty: DNS Codec Input Validation Bypass in Netty (Encoder + Decoder) CVSS 3.1CRITICAL 9.1
- TI-2026-40973 Netty: Missing CertificateID Validation in OCSP Response Allows Replay Attacks CVSS 3.1CRITICAL 9.1
- TI-2026-40972 Uncontrolled resource consumption in netty CVSS 3.1HIGH 7.5
Sources
- CVE-2025-67735 · CVE Program
- CVE-2025-67735 · NVD
- FIRST EPSS
- GHSA-84h7-rjj3-6jx4 · GitHub Advisory Database · CC BY 4.0
- CVE-2025-67735 · Red Hat security data · CC BY 4.0
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