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.
Affected products
netty: netty
References10
- github.com/netty/netty/security/advisories/GHSA-f6hv-jmp6-3vwv ExploitMitigationVendor Advisory
- github.com/netty/netty/security/advisories/GHSA-f6hv-jmp6-3vwv ExploitMitigationVendor Advisory
- access.redhat.com/errata/RHSA-2026:23808
- access.redhat.com/errata/RHSA-2026:24502
- access.redhat.com/errata/RHSA-2026:25123
- access.redhat.com/errata/RHSA-2026:28010
- access.redhat.com/errata/RHSA-2026:34608
- access.redhat.com/errata/RHSA-2026:36820
- access.redhat.com/errata/RHSA-2026:37390
- access.redhat.com/errata/RHSA-2026:41951
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 63 · as of 14 November 2026
- CWE
- CWE-400CWE-770
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