CVE-2026-84997

CVE-2026-84997 · react/http: A malformed HTTP chunked body can lead to a denial-of-service and peg the CPU

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react/http is an event-driven, streaming HTTP client and server implementation for ReactPHP. From 0.6.0 until 1.11.1, React\Http\Io\ChunkedDecoder could enter an infinite loop while processing a malformed Transfer-Encoding: chunked body because handleData required its buffer to shrink on every iteration. An incomplete terminal-chunk trailer without CRLF left the buffer unchanged after strpos returned false, and exactly two non-CRLF bytes after a completed non-terminal chunk bypassed both the error and wait guards. The affected decoder processes request bodies for React\Http\HttpServer and response bodies for React\Http\Browser, allowing a malicious client to freeze a server or a malicious or compromised server to freeze a client. A reverse proxy that normalizes inbound requests may protect the server direction but does not protect outbound Browser requests. This issue is fixed in version 1.11.1.

CVSS 7.5 · High · EPSS 0.7% · Fix available

Published

2026-09-16T14:07:52.948Z

Updated

2026-09-16T14:46:47.220Z

Stack: php

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