GitHub Advisoryadvisory · PyPI

GHSA-63hw-fmq6-xxg2 aiohttp: C HTTP Parser Bypasses max_line_size for Fragmented Lines

MEDIUM Published 2026-06-15 Modified 2026-06-15 Official page ↗
Aliases
CVE-2026-54277
Ecosystem
PyPI
Packages
aiohttp
Severity
Moderate
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
Weaknesses
CWE-770
Reviewed
2026-06-15

Affected packages

• PyPI aiohttp: < 3.14.1 → fixed in 3.14.1

Description

Summary It is possible to bypass the max_line_size 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, potentially leading to DoS. ----- Patch: https://github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804d

Related

Alias · CVE (1)

  • CVE-2026-54277 AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. vulnerability

Weakness · CWE (1)

  • CWE-770 Allocation of Resources Without Limits or Throttling weakness

References