AUGUST 15, 2026
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Case File

CVE-2026-48809

HIGH · CVSS 7.5 EPSS 0.28% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-08-11 · Last synced 2026-08-15

CyberRota Analysis

AI-Generated

Versions of python-engineio prior to 4.13.2 are vulnerable due to inadequate checks on the size of incoming messages, allowing attackers to exploit this flaw through specific configurations, leading to excessive memory allocation. This can result in denial-of-service conditions, impacting the availability of applications using the affected library. Organizations utilizing python-engineio for real-time communications should prioritize upgrading to version 4.13.2 to mitigate this high-severity risk.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-48809
Severity
HIGH
CVSS
7.5
EPSS
0.28%

Original NVD Description

python-engineio is a Python implementation of the Engine.IO realtime client and server. Versions prior to 4.13.2 have two specific configurations of the python-engineio server in which the size of incoming messages is not checked before the messages are loaded into memory. An attacker can take advantage of these to cause unnecessary memory allocations in the python-engineio server. The two cases are POST requests, when using ASGI with the long polling transport and WebSocket messages, when using Aiohttp with the WebSocket transport. Version 4.13.2 addresses this issue. ASGI severs now only load the body of incoming requests into memory after the client is confirmed to be known and authenticated, and the payload size is below the maximum allowed size. Requests that do not comply with these requirements are discarded. Aiohttp servers configure the maximum payload size in the underlying WebSocket layer from Aiohttp, so that large messages are discarded by Aiohttp before they are delivered to python-engineio.