CVE-2026-54277Medium▾ Sunlitaiohttp: C HTTP Parser Bypasses max_line_size for Fragmented Lines
▾ Sunlit zone — Low / medium · no exploitation signal
impact 27.5 · likelihood 0.1 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 7.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
0.3%
Last analysed / modified upstream
It is possible to bypass the max_line_size check in parts of an HTTP request in the C parser.
If using the optimised C parser (the default in pre-built wheels), then an attacker may be able to send oversized lines through the HTTP parser and use an excessive amount of memory, potentially leading to DoS.
Patch: https://github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804d
aiohttp < 3.14.1Upgrade to a patched release:
aiohttp 3.14.1Connected by shared product, vendor, weakness, or advisory.
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