TI-2026-39177 Aliases CVE-2026-54277 GHSA-63hw-fmq6-xxg2

AIOHTTP: C HTTP Parser Bypasses max_line_size for Fragmented Lines

LOW 36CWE-770Published 2026-06-22 · Updated 2026-06-23

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 5 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-770.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00563 47th percentileScored 2026-11-07

Fix Partial aiohttp (aio-libs): 3.14.1aiohttp (PyPI): 3.14.1Red Hat: 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
aio-libs	aiohttp	before 3.14.1	3.14.1	Patch available	CNA
—	aiohttp (PyPI)	before 3.14.1	3.14.1	Patch available	GHSA-63hw-fmq6-xxg2

aiohttp Vendoraio-libs Affected before 3.14.1 Fixed in 3.14.1 Patch available CNA
aiohttp (PyPI) Vendor— Affected before 3.14.1 Fixed in 3.14.1 Patch available GHSA-63hw-fmq6-xxg2

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:aiohttp:aiohttp::::::::	before 3.14.1	Vulnerable	Aiohttp

cpe:2.3:a:aiohttp:aiohttp:*:*:*:*:*:*:*:* Versions before 3.14.1 Vulnerable ·Aiohttp

Remediation

Fix · CNA aiohttp (aio-libs) Fixed in 3.14.1
Fix · GHSA-63hw-fmq6-xxg2 aiohttp (PyPI) Fixed in 3.14.1 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat AI Inference Server	Affected	No fix yet: Fix deferred
Red Hat Discovery 2	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux AI (RHEL AI) 3	Affected	No fix yet: Fix deferred
Red Hat OpenShift AI (RHOAI)	Affected	No fix yet: Fix deferred
Red Hat Satellite 6	Affected	No fix yet: Fix deferred

Not affected: 10 products

Exploit Intelligence
Migration Toolkit for Applications 8
OpenShift Lightspeed
Red Hat AI Inference Server
Red Hat Ansible Automation Platform 2
Red Hat Ansible Automation Platform Ansible Core 2
Red Hat Hardened Images
Red Hat OpenShift AI (RHOAI)
Red Hat Satellite 6
Red Hat Update Infrastructure 4 for Cloud Providers

Timeline

2026-10-02 Threatist record created from CVE-2026-54277
2026-10-03 Alias added: GHSA-63hw-fmq6-xxg2

References

TI-2025-38826 aiomysql allows arbitrary access to client files through vulnerability of a malicious MySQL server CVSS 4.0HIGH 8.2
TI-2024-15436 aiohttp.web.static(follow_symlinks=True) is vulnerable to directory traversal CVSS 3.1HIGH 7.5
TI-2023-25769 Request smuggling in aiohttp CVSS 3.1HIGH 7.5
TI-2023-18906 aiohttp vulnerable to HTTP request smuggling CVSS 3.1HIGH 7.5
TI-2023-26746 aiohttp's ClientSession is vulnerable to CRLF injection via version CVSS 3.1HIGH 7.2
TI-2026-66145 Multidict: Reference leak in CIMultiDict/MultiDict items-view union and subtraction CVSS 3.1MEDIUM 5.3

See all 59 →

Sources

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