CVE-2025-53643Low▾ SunlitAIOHTTP is vulnerable to HTTP Request/Response Smuggling through incorrect parsing of chunked trailer sections
▾ Sunlit zone — Low / medium · no exploitation signal
impact 13.8 · likelihood 0.1 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 8.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
0.3%
0.3% → 0.3%
Last analysed / modified upstream
The Python parser is vulnerable to a request smuggling vulnerability due to not parsing trailer sections of an HTTP request.
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
aiohttp < 3.12.14Upgrade to a patched release:
aiohttp 3.12.14Connected by shared product, vendor, weakness, or advisory.
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