CVE-2026-54277
HIGHAIOHTTP: C HTTP Parser Bypasses max_line_size for Fragmented Lines
Title source: cnaDescription
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, 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. This vulnerability is fixed in 3.14.1.
References (2)
Core 2
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-63hw-fmq6-xxg2
X_Refsource_Misc x_refsource_misc
https://github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804d
Scores
CVSS v3
7.5
EPSS
0.0032
EPSS Percentile
24.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-770
Status
published
Products (2)
aio-libs/aiohttp
< 3.14.1
aiohttp/aiohttp
< 3.14.1
Published
Jun 22, 2026
Tracked Since
Jun 22, 2026