CVE-2026-54277

A flaw was found in aiohttp, an asynchronous HTTP client/server framework for Python. A remote attacker can exploit this vulnerability by sending oversized lines within an HTTP request. This bypasses the maxlinesize check in the C parser, causing the system to use an excessive amount of memory...

CVE-2026-54277

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, it is possible to bypass the maxlinesize 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...

CVE-2026-54277

CVE-2026-54277 affects AIOHTTP prior to 3.14.1 where the max_line_size check in parts of the C HTTP parser can be bypassed, allowing an attacker to send oversized lines and cause excessive memory use leading to DoS. The issue occurs when using the optimized C parser (default in pre-built wheels)....

GHSA-63HW-FMQ6-XXG2 aiohttp: C HTTP Parser Bypasses max_line_size for Fragmented Lines

Summary It is possible to bypass the maxlinesize check in parts of an HTTP request in the C parser. Impact 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, potential...

PT-2026-49591

Name of the Vulnerable Software and Affected Versions AIOHTTP versions prior to 3.14.1 Description An issue exists in the C parser of the asynchronous HTTP client/server framework where the max line size check can be bypassed in parts of an HTTP request. When using the optimized C parser, which i...