PYSEC-2026-1104
AIOHTTP is vulnerable to HTTP Request/Response Smuggling through incorrect parsing of chunked trailer sections
At a glance
- Published
- Updated
- CVE
- CVE-2025-53643
- Aliases
- GHSA-9548-qrrj-x5pj
- CVSS_V4
- CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U
Description
### Summary The Python parser is vulnerable to a request smuggling vulnerability due to not parsing trailer sections of an HTTP request. ### 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/e8d774f635dc6d1cd3174d0e38891da5de0e2b6a
Affected packages
| Package | Versions |
|---|---|
| PyPI · aiohttp | introduced 0, fixed 3.12.14 |
References
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-9548-qrrj-x5pj WEB
- https://nvd.nist.gov/vuln/detail/CVE-2025-53643 ADVISORY
- https://github.com/aio-libs/aiohttp/commit/e8d774f635dc6d1cd3174d0e38891da5de0e2b6a FIX
- https://github.com/aio-libs/aiohttp PACKAGE
- https://pypi.org/project/aiohttp PACKAGE
- https://github.com/advisories/GHSA-9548-qrrj-x5pj ADVISORY
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — PyPA Advisory Database |