CVE-2026-34516CWE-770

AIOHTTP: Multipart Header Size Bypass

Medium · published April 1, 2026

CVSS v4.0
6.6
EPSS
1%
Percentile
48.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
6.6 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
EPSS
0.00609 · 48.5th percentile
Weakness
CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-04-01T20:13Z
EPSS history
Timeline
  • 01 APR 20:13Z
    AIOHTTP: Multipart Header Size Bypass
    cvelistv5