AIOHTTP's unicode processing of header values could cause parsing discrepancies
### Summary The Python HTTP parser may allow a request smuggling attack with the presence of non-ASCII characters. ### Impact If a pure Python version of aiohttp is installed (i.e. without the usual C extensions) or AIOHTTP_NO_EXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections. ------ Patch: https://github.com/aio-libs/aiohttp/commit/32677f2adfd907420c078dda6b79225c6f4ebce0
02 / AFFECTED SOFTWARE
Affected packages
150 explicit affected versions
303 explicit affected versions
303 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
### Summary The Python HTTP parser may allow a request smuggling attack with the presence of non-ASCII characters. ### Impact If a pure Python version of aiohttp is installed (i.e. without the usual C extensions) or AIOHTTP_NO_EXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections. ------ Patch: https://github.com/aio-libs/aiohttp/commit/32677f2adfd907420c078dda6b79225c6f4ebce0
### Summary The Python HTTP parser may allow a request smuggling attack with the presence of non-ASCII characters. ### Impact If a pure Python version of aiohttp is installed (i.e. without the usual C extensions) or AIOHTTP_NO_EXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections. ------ Patch: https://github.com/aio-libs/aiohttp/commit/32677f2adfd907420c078dda6b79225c6f4ebce0
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Versions 3.13.2 and below of the Python HTTP parser may allow a request smuggling attack with the presence of non-ASCII characters. If a pure Python version of AIOHTTP is installed (i.e. without the usual C extensions) or AIOHTTP_NO_EXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections. This issue is fixed in version 3.13.3.
05 / REFERENCES
Further evidence
- https://github.com/aio-libs/aiohttp
- https://github.com/aio-libs/aiohttp/commit/32677f2adfd907420c078dda6b79225c6f4ebce0
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-69f9-5gxw-wvc2
- https://nvd.nist.gov/vuln/detail/CVE-2025-69224
- https://github.com/advisories/GHSA-69f9-5gxw-wvc2
- https://pypi.org/project/aiohttp
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/69xxx/CVE-2025-69224.json