Allocation of Resources Without Limits or Throttling Affecting python-engineio package, versions <4.14.0-1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.49% (40th percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-PYTHONENGINEIO-18860664
  • published16 Aug 2026
  • disclosed11 Aug 2026

Introduced: 11 Aug 2026

CVE-2026-48809  (opens in a new tab)
CWE-770  (opens in a new tab)

How to fix?

Upgrade Debian:unstable python-engineio to version 4.14.0-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream python-engineio package and not the python-engineio package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1