CVE-2026-34525

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000	Patch
https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349	Patch
https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4	Release Notes
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67	Patch Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:aiohttp:aiohttp:*:*:*:*:*:*:*:*

History

16 Apr 2026, 16:21

Type	Values Removed	Values Added
CPE		cpe:2.3:a:aiohttp:aiohttp::::::::
First Time		Aiohttp aiohttp Aiohttp
References	~~() https://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000 -~~	() https://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000 - Patch
References	~~() https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349 -~~	() https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349 - Patch
References	~~() https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4 -~~	() https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4 - Release Notes
References	~~() https://github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67 -~~	() https://github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67 - Patch, Vendor Advisory
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 5.3

01 Apr 2026, 21:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-01 21:17

Updated : 2026-04-16 16:21

NVD link : CVE-2026-34525

Mitre link : CVE-2026-34525

CVE.ORG link : CVE-2026-34525

JSON object : View

Products Affected

aiohttp

aiohttp

CWE

CWE-20

Improper Input Validation

CWE-444

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

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