High 7.5Published Apr 1, 2026

CVE-2026-34516AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python.

Updated under an hour ago (2026-10-19 06:25 UTC)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, a response with an excessive number of multipart headers may be allowed to use more memory than intended, potentially allowing a DoS vulnerability. This issue has been patched in version 3.13.4.

CVSS: 7.5 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-770
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Analyzed
Record last updated: Jun 17, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

aiohttp aiohttp aiohttp:aiohttp	before 3.13.4	NVD

References

https://github.com/aio-libs/aiohttp/commit/8a74257b3804c9aac0bf644af93070f68f6c5a6fpatch
https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4release-notes
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-m5qp-6w8w-w647patch, vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.