Medium severity · published Apr 1, 2026
CVE-2026-34514
AIOHTTP: CRLF injection in multipart part content type header construction
5.3
CVSS
0.3%
EPSS
No
On KEV
Description
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, an attacker who controls the content_type parameter in aiohttp could use this to inject extra headers or similar exploits. This issue has been patched in version 3.13.4.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 24% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AI
aiohttp · aio-libs
< 3.13.4 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-34514
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-34514
Patch
https://github.com/aio-libs/aiohttp/commit/9a6ada97e2c6cf1ce31727c6c9fcea17c21f6f06
Release Notes
https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
Patch
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-2vrm-gr82-f7m5
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