---
id: CVE-2026-34514
aliases:
  - GHSA-2vrm-gr82-f7m5
  - PYSEC-2026-2096
title: >-
  AIOHTTP has CRLF injection through multipart part content type header
  construction
summary: >-
  AIOHTTP has CRLF injection through multipart part content type header
  construction
severity: low
vendor: aiohttp
product: aiohttp
ecosystem: pip
affected:
  - aiohttp < 3.13.4
patched:
  - aiohttp 3.13.4
published: '2026-04-01'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:50:42.288164171Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-2vrm-gr82-f7m5'
references:
  - url: >-
      https://github.com/aio-libs/aiohttp/security/advisories/GHSA-2vrm-gr82-f7m5
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-34514'
  - url: >-
      https://github.com/aio-libs/aiohttp/commit/9a6ada97e2c6cf1ce31727c6c9fcea17c21f6f06
  - url: 'https://github.com/aio-libs/aiohttp'
  - url: 'https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4'
tags:
  - osv
  - pip
epss: 0.00398
epssPercentile: 0.31295
ingestedAt: '2026-07-13T18:57:51.530Z'
---

## Overview

### Summary

An attacker who controls the `content_type` parameter in aiohttp could use this to inject extra headers or similar exploits.

### Impact

If an application allows untrusted data to be used for the multipart `content_type` parameter when constructing a request, an attacker may be able to manipulate the request to send something other than what the developer intended.

-----

Patch: https://github.com/aio-libs/aiohttp/commit/9a6ada97e2c6cf1ce31727c6c9fcea17c21f6f06

## Affected packages

- `aiohttp < 3.13.4`

## Remediation

Upgrade to a patched release:

- `aiohttp 3.13.4`