---
schema_version: '1.0'
id: security-20260714-1848ab
url: https://osv.dev/vulnerability/PYSEC-2026-2103
url_hash: 1848ab95d70282e0581e61e636587036993cd116375298198f7da38e70dabd8f
canonical_url: https://osv.dev/vulnerability/PYSEC-2026-2103
source: osv:pypa
category: security/library
category_raw: cve/library
region: null
tags:
- cve
- CVE-2026-34525
- PYSEC-2026-2103
- severity:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- aiohttp
- PyPI
lang: en
published_at: '2026-04-01T21:17:00Z'
fetched_at: '2026-07-14T06:42:23Z'
updated_at: '2026-07-14T06:42:55Z'
status: published
content_hash: 23b09e9965102f0b4e63774ba43e2ffd93c23fbf7f40f8a4e5544483e493eb3d
license_note: full
summary: AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python.
  Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue
  has been patched in version 3.13.4.
summary_source: rss
summary_en: AIOHTTP is an asynchronous HTTP client/server framework for asyncio and
  Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp.
  This issue has been patched in version 3.13.4.
entities: []
key_facts: []
related: []
related_auto: []
title: CVE-2026-34525 — aiohttp
---

# CVE-2026-34525 — aiohttp

## TL;DR
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.

## Key Points
- cve / CVE-2026-34525 / PYSEC-2026-2103 / severity:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N / aiohttp / PyPI

## Details
**Severity:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
**Advisory:** PYSEC-2026-2103 (CVE-2026-34525)

**Affected (your watchlist):**
- `PyPI:aiohttp` 3.13.3 → fixed in 3.13.4 [docker/docker-strands]

**Details:**
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.

**References:**
- https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
- https://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000
- https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67

_Data: OSV.dev (upstream: pypa) — https://osv.dev/vulnerability/PYSEC-2026-2103_

## Source
元記事: [CVE-2026-34525 — aiohttp](https://osv.dev/vulnerability/PYSEC-2026-2103) — published 2026-04-01T21:17:00Z