---
id: CVE-2026-54278
aliases:
  - GHSA-g3cq-j2xw-wf74
  - PYSEC-2026-2111
title: >-
  aiohttp: Unread Compressed Request Bodies Bypass client_max_size During
  Cleanup
summary: >-
  aiohttp: Unread Compressed Request Bodies Bypass client_max_size During
  Cleanup
severity: medium
vendor: aiohttp
product: aiohttp
ecosystem: pip
affected:
  - aiohttp < 3.14.1
patched:
  - aiohttp 3.14.1
published: '2026-06-15'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:51:08.751749295Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-g3cq-j2xw-wf74'
references:
  - url: >-
      https://github.com/aio-libs/aiohttp/security/advisories/GHSA-g3cq-j2xw-wf74
  - url: 'https://github.com/aio-libs/aiohttp'
  - url: 'https://github.com/advisories/GHSA-g3cq-j2xw-wf74'
tags:
  - osv
  - pip
  - ghsa
epss: 0.00493
epssPercentile: 0.39785
cwe:
  - CWE-409
ingestedAt: '2026-07-07T15:41:58.688Z'
---

## Overview

### Summary

During cleanup it is possible for a compressed request body to be decompressed into memory in one chunk.

### Impact

An attacker may be able to send a compressed payload in specific situations that could be decompressed into memory, potentially leading to DoS (a zip bomb edge case).

### Workaround

Disable compression if unable to upgrade.

-----

Patch: https://github.com/aio-libs/aiohttp/commit/4f7480e474cccc6a8cc2c92ad3f17a31dedf8232

## Affected packages

- `aiohttp < 3.14.1`

## Remediation

Upgrade to a patched release:

- `aiohttp 3.14.1`