High severity · published Mar 27, 2026
CVE-2026-33870
Netty: HTTP Request Smuggling via Chunked Extension Quoted-String Parsing
7.5
CVSS
0.7%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 53% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NE
netty · netty
< 4.1.132.Final; >= 4.2.0.Alpha1, < 4.2.10.Final · source: vendor, NVD
C4
Cryostat 4 on RHEL 9 · Red Hat
All versions, or not specified · source: CISA
LS
Logging Subsystem for Red Hat OpenShift · Red Hat
All versions, or not specified · source: CISA
OS
OpenShift Serverless · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat AMQ Broker 7.12.7 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat AMQ Broker 7.13.5 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat AMQ Broker 7.14.0 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat AMQ Clients · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Build of Apache Camel 4.14 for Quarkus 3.27 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Build of Keycloak · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Data Grid 8.6.1 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux AI (RHEL AI) 3 · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33870
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-33870
Exploit
https://github.com/netty/netty/security/advisories/GHSA-pwqr-wmgm-9rr8
Technical Description
https://w4ke.info/2025/06/18/funky-chunks.html
Technical Description
https://w4ke.info/2025/10/29/funky-chunks-2.html
Technical Description
https://www.rfc-editor.org/rfc/rfc9110
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:10175
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:10184
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