Netty: HttpContentDecompressor maxAllocation bypass via Content-Encoding: br/zstd/snappy enables decompression bomb DoS

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Summary

CVECVE-2026-42587
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-05-13 19:17:24 UTC
Updated2026-07-03 13:17:13 UTC
DescriptionNetty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpContentDecompressor accepts a maxAllocation parameter to limit decompression buffer size and prevent decompression bomb attacks. This limit is correctly enforced for gzip and deflate encodings via ZlibDecoder, but is silently ignored when the content encoding is br (Brotli), zstd, or snappy. An attacker can bypass the configured decompression limit by sending a compressed payload with Content-Encoding: br instead of Content-Encoding: gzip, causing unbounded memory allocation and out-of-memory denial of service. The same vulnerability exists in DelegatingDecompressorFrameListener for HTTP/2 connections. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS: 0.000180000 probability, percentile 0.048440000 (date 2026-05-25)

Problem Types: CWE-400 | CWE-770 | CWE-400 CWE-400: Uncontrolled Resource Consumption | CWE-770 Allocation of Resources Without Limits or Throttling

VersionSourceTypeScoreSeverityVector
3.1ADPCVSS7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1[email protected]Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.10b0ca135-0b70-47e7-9f44-1890c2a1c46cSecondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Netty Netty All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Netty Netty affected >= 4.2.0.Alpha1, < 4.2.13.Final Not specified
CNA Netty Netty affected < 4.1.133.Final Not specified
CNA Io.netty Netty-codec-http affected >= 4.2.0.Alpha1, < 4.2.13.Final Not specified
CNA Io.netty Netty-codec-http affected < 4.1.133.Final Not specified
CNA Io.netty Netty-codec-http2 affected >= 4.2.0.Alpha1, < 4.2.13.Final Not specified
CNA Io.netty Netty-codec-http2 affected < 4.1.133.Final Not specified
ADP Red Hat Cryostat 4 On RHEL 9 Not specified Not specified
ADP Red Hat Red Hat OpenShift Dev Spaces 3.28 Not specified Not specified
ADP Red Hat Red Hat Build Of Quarkus 3.27.4 Not specified Not specified
ADP Red Hat Red Hat Build Of Quarkus 3.33.2 Not specified Not specified
ADP Red Hat Streams For Apache Kafka 2.9.4 Not specified Not specified
ADP Red Hat Cryostat 4 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 For Spring Boot 4 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 OptaPlanner 8 Not specified Not specified
ADP Red Hat Red Hat Data Grid 8 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 Dev Spaces Not specified Not specified
ADP Red Hat Red Hat Process Automation 7 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
ADP Red Hat Red Hat Build Of Apache Camel 4 For Quarkus 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 Satellite 6 Not specified Not specified

References

ReferenceSourceLinkTags
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-2026-42587.json 0b0ca135-0b70-47e7-9f44-1890c2a1c46c security.access.redhat.com
access.redhat.com/errata/RHSA-2026:34608 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
github.com/netty/netty/security/advisories/GHSA-f6hv-jmp6-3vwv 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com Exploit, Mitigation, Vendor Advisory
access.redhat.com/security/cve/CVE-2026-42587 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

Additional Advisory Data

SourceTimeEvent
ADP2026-05-13T19:01:35.415ZReported to Red Hat.
ADP2026-05-13T18:22:21.699ZMade public.

Solutions

ADP: RHSA-2026:28010: Cryostat 4 on RHEL 9

ADP: RHSA-2026:25123: Red Hat OpenShift Dev Spaces 3.28

ADP: RHSA-2026:23808: Red Hat build of Quarkus 3.27.4

ADP: RHSA-2026:24502: Red Hat build of Quarkus 3.33.2

ADP: RHSA-2026:34608: Streams for Apache Kafka 2.9.4

Workarounds

ADP: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

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