CVE-2026-34516 — HIGH (7.5)

Q: How severe is CVE-2026-34516?

CVE-2026-34516 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.

Q: Is there a patch for CVE-2026-34516?

Check the references section above for vendor advisories and patch information. Affected products include: Aiohttp Aiohttp.

Vulnerability Description

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 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Affected Products

Vendor	Product	Versions
Aiohttp	Aiohttp	< 3.13.4

Related Weaknesses (CWE)

CWE-770

References

https://github.com/aio-libs/aiohttp/commit/8a74257b3804c9aac0bf644af93070f68f6c5Patch
https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4Release Notes
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-m5qp-6w8w-w647PatchVendor Advisory

FAQ

What is CVE-2026-34516?

CVE-2026-34516 is a vulnerability with a CVSS score of 7.5 (HIGH). 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...

How severe is CVE-2026-34516?

CVE-2026-34516 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-34516?

Check the references section above for vendor advisories and patch information. Affected products include: Aiohttp Aiohttp.