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CVE-2026-42587

CVE-2026-42587 · Netty: HttpContentDecompressor maxAllocation bypass via Content-Encoding: br/zstd/snappy enables decompression bomb DoS

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 7.5 · High · EPSS 1.0%

Published
Updated

Stack: system

Affected products and versions

  • netty

    Versions
    • >= 4.2.0.Alpha1, < 4.2.13.Final: Affected
    • < 4.1.133.Final: Affected

    No fix published

  • netty-codec-http

    Versions
    • >= 4.2.0.Alpha1, < 4.2.13.Final: Affected
    • < 4.1.133.Final: Affected

    No fix published

  • netty-codec-http2

    Versions
    • >= 4.2.0.Alpha1, < 4.2.13.Final: Affected
    • < 4.1.133.Final: Affected

    No fix published

  • netty Debian:12

    Versions
    • 1:4.1.48-10
    • 1:4.1.48-11
    • 1:4.1.48-12
    • 1:4.1.48-13
    • 1:4.1.48-14
    • 1:4.1.48-15
    • 1:4.1.48-16
    • 1:4.1.48-7
    • 1:4.1.48-7+deb12u1
    • 1:4.1.48-7+deb12u2
    • 1:4.1.48-8
    • 1:4.1.48-9
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • netty Debian:13

    Versions
    • 1:4.1.48-10
    • 1:4.1.48-10+deb13u1
    • 1:4.1.48-11
    • 1:4.1.48-12
    • 1:4.1.48-13
    • 1:4.1.48-14
    • 1:4.1.48-15
    • 1:4.1.48-16
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • netty Debian:14

    Versions
    • 1:4.1.48-10
    • 1:4.1.48-11
    • 1:4.1.48-12
    • 1:4.1.48-13
    • 1:4.1.48-14
    • 1:4.1.48-15
    • 1:4.1.48-16
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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