CVE-2023-47627 Request smuggling in aiohttp
Request smuggling in aiohttp HTTP parser when extensions are disabled, allowing attackers to bypass security controls.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-47627?
CVE-2023-47627 is a medium-severity vulnerability in aio-libs aiohttp, published on 14 Nov 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. The HTTP parser in AIOHTTP has numerous problems with header parsing, which could lead to request smuggling. This parser is only used when AIOHTTP_NO_EXTENSIONS is enabled (or not using a prebuilt wheel). These bugs have been addressed in commit `d5c12ba89` which has been included in release version 3.8.6. Users are advised to upgrade. There are no known workarounds for these issues.
Weakness: CWE-444
Which versions are affected by CVE-2023-47627?
3 open source packages ship an affected version, including aiohttp. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
aiohttp PyPI | All versions | 3.8.6 |
aiohttp PyPI | All versions | 3.8.6 |
aiohttp PyPI | All versions | 3.8.6 |
Linux distribution packages (1)
python-aiohttp openSUSE:Tumbleweed | All versions | 3.9.0-1.1 |
Products include Aiohttp Aiohttp.
How do I fix CVE-2023-47627?
Upgrade aiohttp to 3.8.6 or later.
Is CVE-2023-47627 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-47627 exists.
Other vulnerabilities in aio-libs aiohttp
- CVE-2024-52303 aiohttp memory leak when middleware is enabled when requesting a resource with a non-allowed method
- CVE-2025-69223 AIOHTTP's HTTP Parser auto_decompress feature is vulnerable to zip bomb
- CVE-2024-30251 Denial of service when trying to parse malformed POST requests in aiohttp
- CVE-2023-49081 aiohttp's ClientSession is vulnerable to CRLF injection via version
- CVE-2026-22815 AIOHTTP: Uncapped memory usage possible through aiohttp allowing unlimited trailer headers
Sources
Also known as AZL-43882, AZL-44370, CLSA-2025-1756253594, DEBIAN-CVE-2023-47627, GHSA-gfw2-4jvh-wgfg, PYSEC-2023-246 and 2 more.