High severity · published Jun 12, 2026
CVE-2026-48043
netty-codec-http2: ByteBuf Reference-Count Leak in DelegatingDecompressorFrameListener Leads to Memory Exhaustion
7.5
CVSS
0.8%
EPSS
No
On KEV
Description
Netty is a network application framework for development of protocol servers and clients. In netty-codec-http2 prior to versions 4.1.135.Final and 4.2.15.Final, the `DelegatingDecompressorFrameListener` class orchestrates HTTP/2 decompression by embedding a per-stream `EmbeddedChannel` that runs the appropriate decompression codec (gzip, deflate, zstd) and forwards decompressed chunks to a wrapped listener. Each decompressed chunk is a pooled `ByteBuf` handed to an anonymous `ChannelInboundHandlerAdapter` tail handler, which becomes the sole owner responsible for releasing it. A remote peer could send frames that would result in the flow-controller throwing and so trigger a resource leak which at the end might take down the whole JVM due OOME. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.8% · higher than 55% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NE
netty · netty
>= 4.2.0.Final, < 4.2.15.Final; < 4.1.135.Final · source: vendor, NVD
C4
Cryostat 4 on RHEL 9 · 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 7.14.1 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1 · 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 8.6.2 · 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
RH
Red Hat Fuse 7 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 9 · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-48043
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-48043
Release Notes
https://github.com/netty/netty/releases/tag/netty-4.1.135.Final
Release Notes
https://github.com/netty/netty/releases/tag/netty-4.2.15.Final
Vendor Advisory
https://github.com/netty/netty/security/advisories/GHSA-c2gf-v879-257j
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26017
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26018
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26586
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