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OpenAdvisories
Medium · 6.6 CVE-2026-54277 EUVD-2026-38314GHSA-63hw-fmq6-xxg2PYSEC-2026-2110

AIOHTTP: C HTTP Parser Bypasses max_line_size for Fragmented Lines

Published Jun 22, 2026 · Updated Jun 23, 2026 · Assigned by GitHub_M

Description

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.

Affected products

VendorProductAffectedFixed
aio-libs aiohttp < 3.14.1 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 python-aiohttp 3.14.1-1 —
Debian 13 python-aiohttp No fix yet —
Debian 12 python-aiohttp 3.8.4-1+deb12u2 —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 python-aiohttp No fix yet —
Ubuntu 25.10 python-aiohttp No fix yet —
Show 6 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 26.04 LTS python-aiohttp No fix yet —
Ubuntu Pro 24.04 LTS python-aiohttp No fix yet —
Ubuntu Pro 22.04 LTS python-aiohttp No fix yet —
Ubuntu Pro 20.04 LTS python-aiohttp No fix yet —
Ubuntu Pro 18.04 LTS python-aiohttp No fix yet —
Ubuntu Pro 16.04 LTS python-aiohttp No fix yet —
ReleasePackageFixed inAdvisory
SLES 15 SP7 python-aiohttp 3.6.0-150100.3.38.1 SUSE-SU-2026:3208-1
SLES 15 SP6 python-aiohttp 3.6.0-150100.3.38.1 SUSE-SU-2026:3208-1, SUSE-SU-2026:3207-1
SLES 15 SP5 python-aiohttp 3.6.0-150100.3.38.1 SUSE-SU-2026:3208-1, SUSE-SU-2026:3207-1
SLES 15 SP4 python-aiohttp 3.6.0-150100.3.38.1 SUSE-SU-2026:3208-1, SUSE-SU-2026:3207-1
SLES 3 python-aiohttp 3.9.3-150400.10.43.1 SUSE-SU-2026:3207-1
Show 7 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 python-aiohttp 3.11.16-160000.6.1 SUSE-SU-2026:22819-1
SLES for SAP 15 SP6 python-aiohttp 3.9.3-150400.10.43.1 SUSE-SU-2026:3207-1
SLES for SAP 15 SP5 python-aiohttp 3.9.3-150400.10.43.1 SUSE-SU-2026:3207-1
SLES for SAP 15 SP4 python-aiohttp 3.9.3-150400.10.43.1 SUSE-SU-2026:3207-1
SLES 16.0 python-aiohttp 3.11.16-160000.6.1 SUSE-SU-2026:22819-1
SLE HPC 15 SP5 python-aiohttp 3.9.3-150400.10.43.1 SUSE-SU-2026:3207-1
SLE HPC 15 SP4 python-aiohttp 3.9.3-150400.10.43.1 SUSE-SU-2026:3207-1
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed python-aiohttp 3.14.1-1.1 openSUSE-SU-2026:11097-1
openSUSE Leap 16.0 python-aiohttp 3.11.16-160000.6.1 openSUSE-SU-2026:21372-1

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 python-aiohttp No fix yet —

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 python39-oci-sdk +1 2.187.0-1.0.5.el9 ELSA-2026-604898

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling airflow-3 3.2.2-r7 —
Wolfi rolling open-webui 0.9.6-r5 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI aiohttp < 3.14.1 3.14.1 GHSA-63hw-fmq6-xxg2

Advisories 6

References