AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, an attacker who controls the reason parameter when creating a Response may be able to inject extra headers or similar exploits. This issue has been patched in version 3.13.4.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-mwh4-6h8g-pg8w AIOHTTP has HTTP response splitting via \r in reason phrase
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 02 Apr 2026 20:30:00 +0000

Type Values Removed Values Added
First Time appeared Aio-libs
Aio-libs aiohttp
Vendors & Products Aio-libs
Aio-libs aiohttp
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 02 Apr 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1286
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}

threat_severity

Moderate


Wed, 01 Apr 2026 23:45:00 +0000

Type Values Removed Values Added
Description AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, an attacker who controls the reason parameter when creating a Response may be able to inject extra headers or similar exploits. This issue has been patched in version 3.13.4.
Title AIOHTTP: HTTP response splitting via \r in reason phrase
Weaknesses CWE-113
References
Metrics cvssV4_0

{'score': 2.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-04-02T15:40:13.945Z

Reserved: 2026-03-30T16:03:31.047Z

Link: CVE-2026-34519

cve-icon Vulnrichment

Updated: 2026-04-02T15:40:10.158Z

cve-icon NVD

Status : Received

Published: 2026-04-01T21:17:00.170

Modified: 2026-04-01T21:17:00.170

Link: CVE-2026-34519

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-04-01T20:26:25Z

Links: CVE-2026-34519 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-04-02T20:16:39Z

Weaknesses