CVE-2026-34516
Memory Exhaustion DoS in AIOHTTP Multipart Header Handling
Publication date: 2026-04-01
Last updated on: 2026-04-15
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| aiohttp | aiohttp | to 3.13.4 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-770 | The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in AIOHTTP, an asynchronous HTTP client/server framework for asyncio and Python. Before version 3.13.4, if a response contained an excessive number of multipart headers, it could consume more memory than intended. This excessive memory usage could potentially be exploited to cause a denial of service (DoS) condition.
How can this vulnerability impact me? :
The vulnerability can lead to a denial of service (DoS) attack by allowing an attacker to cause the application to use excessive memory when processing responses with many multipart headers. This could degrade the performance or availability of the affected service.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade AIOHTTP to version 3.13.4 or later, where the issue has been patched.