VULNERABILITY INTELLIGENCE

CVE-2026-42587

CVSS score7.5 HIGH
EPSS probability0.99%
CISA KEVNot currently listed
Published2026-05-13
Last modified2026-10-26
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Weakness classification

  • security-advisories@github.com: CWE-400
  • 0b0ca135-0b70-47e7-9f44-1890c2a1c46c: CWE-770

Primary references