CVE-2026-42587: Netty: HttpContentDecompressor maxAllocation bypass via Content-Encoding: br/zstd/snappy enables decompression bomb DoS
Description
Netty 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.
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H · CWE-400
Tracked companies
Mapped from the CVE’s affected-product data, NVD CPE matches, vendor advisories or package feeds. A mapping means the vendor’s software is named, not that its hosted service was exposed.
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
io.netty: netty-codec-httpio.netty: netty-codec-http2netty: nettyRed Hat: Cryostat 4Red Hat: Red Hat AMQ Broker 7.13.6Red Hat: Red Hat AMQ Broker 7.14.1Red Hat: Red Hat AMQ ClientsRed Hat: Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16Red Hat: Red Hat build of Apache Camel 4 for Quarkus 3Red Hat: Red Hat build of Apicurio Registry 3Red Hat: Red Hat build of Debezium 3Red Hat: Red Hat Build of KeycloakRed Hat: Red Hat Data Grid 8.6.2Red Hat: Red Hat Enterprise Linux AI (RHEL AI) 3Red Hat: Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7Red Hat: Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8Red Hat: Red Hat JBoss Enterprise Application Platform 8.1.7.GARed Hat: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10Red Hat: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat: streams for Apache Kafka 2Red Hat: Streams for Apache Kafka 2.9.4Red Hat: Streams for Apache Kafka 3.2.1
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- github.com/netty/netty/security/advisories/GHSA-f6hv-jmp6-3vwv (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)