CVE-2026-84997

High

Description

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.

SeverityHigh
CVSS7.5
Exploit probability—
ProductReact/http
PublishedSep 16, 2026
First seenSep 16, 2026
Weakness typeCWE-835CWE-835

How to fix

Update
  • react/http1.11.1 or later

Affected products

ProductAffected versionsFixed in
react/httpPackagist0.6.0 ≤ v < 1.11.11.11.1

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