CVE-2026-84997CWE-835

CVE-2026-84997

High · published September 16, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
50.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00655 · 50.8th percentile
Weakness
CWE-835 · Loop with Unreachable Exit Condition ('Infinite Loop')
Published
2026-09-16T19:18Z
References (4)
EPSS history
Timeline
  • 18 SEP 04:02Z
    EPSS moved — → 1%
    epss
  • 16 SEP 14:07Z
    react/http: A malformed HTTP chunked body can lead to a denial-of-service and peg the CPU
    cvelistv5