CyberSecBulletin
CVE-2026-33870NVD status: Modified

netty: Inconsistent Interpretation of HTTP Requests

Published Updated By the CyberSecBulletin desk

CVE-2026-33870 is a high-severity inconsistent interpretation of HTTP requests vulnerability in netty, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected netty versions: < 4.1.132.Final; >= 4.2.0.Alpha1, < 4.2.10.Final. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.72% chance of exploitation within 30 days, higher than 54% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of netty you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Nettynetty< 4.1.132.Final; >= 4.2.0.Alpha1, < 4.2.10.FinalNot stated
Red HatCryostat 4 on RHEL 9Not specified in the recordNot stated
Red HatRed Hat AMQ Broker 7.12.7Not specified in the recordNot stated
Red HatRed Hat AMQ Broker 7.13.5Not specified in the recordNot stated
Red HatRed Hat AMQ Broker 7.14.0Not specified in the recordNot stated
Red HatRed Hat Build of Apache Camel 4.14 for Quarkus 3.27Not specified in the recordNot stated
Red HatRed Hat build of Apache Camel 4.18.1 for Spring Boot 3.5.14Not specified in the recordNot stated
Red HatRed Hat build of Quarkus 3.20.6Not specified in the recordNot stated
Red HatRed Hat build of Quarkus 3.27.3Not specified in the recordNot stated
Red HatRed Hat Data Grid 8.6.1Not specified in the recordNot stated
Red HatRed Hat JBoss Enterprise Application Platform 8.1Not specified in the recordNot stated
Red HatRed Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Not specified in the recordNot stated
Red HatRed Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Not specified in the recordNot stated
Red HatStreams for Apache Kafka 2.9.4Not specified in the recordNot stated
Red HatStreams for Apache Kafka 3.2.0Not specified in the recordNot stated
Red HatRed Hat OpenShift AI 2.25Not specified in the recordNot stated
Red HatRed Hat OpenShift Dev Spaces 3.27Not specified in the recordNot stated
Red HatLogging Subsystem for Red Hat OpenShiftNot specified in the recordNot stated
Red HatOpenShift ServerlessNot specified in the recordNot stated
Red HatRed Hat AMQ ClientsNot specified in the recordNot stated
Red HatRed Hat build of Apache Camel 4 for Quarkus 3Not specified in the recordNot stated
Red HatRed Hat build of Apache Camel - HawtIO 4Not specified in the recordNot stated
Red HatRed Hat build of Apicurio Registry 2Not specified in the recordNot stated
Red HatRed Hat build of Apicurio Registry 3Not specified in the recordNot stated
Red HatRed Hat build of Debezium 3Not specified in the recordNot stated

Version data comes from the organisation that assigned the CVE; 11 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by CNA (github.com).

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA (github.com)
CVSS 3.17.5HighCNA

Official description

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, Netty incorrectly parses quoted strings in HTTP/1.1 chunked transfer encoding extension values, enabling request smuggling attacks. Versions 4.1.132.Final and 4.2.10.Final fix the issue.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Inconsistent Interpretation of HTTP Requests

The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

How developers prevent this class of flaw

  • Use a web server that employs a strict HTTP parsing procedure, such as Apache.
  • Terminate the client session after each request.

More Inconsistent Interpretation of HTTP Requests vulnerabilities (CWE-444)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in netty

All netty vulnerabilities

Recent Inconsistent Interpretation of HTTP Requests vulnerabilities

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