VulnerabilityAnalyzed

CVE-2026-34517

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python.

LOW 2.7EPSS 0.38%

Does this matter?

Lower severity and a low EPSS score (0.38%). Track it; it rarely justifies an emergency change on its own.

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, for some multipart form fields, aiohttp read the entire field into memory before checking client_max_size. This issue has been patched in version 3.13.4.

CVSS 4.0: 2.7 LOWCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.38% probability · 32th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-770
Affected: aiohttp/aiohttp
Source: security-advisories@github.com

EPSS trend

EPSS 0.4% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

https://github.com/aio-libs/aiohttp/commit/cbb774f38330563422ca0c413a71021d7b944145Patch
https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4Release Notes
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-3wq7-rqq7-wx6jPatch, Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.