Memory Consumption Vulnerability in AIOHTTP Framework by aio-libs
CVE-2026-128129

8.2HIGH

Key Information:

Vendor

Aio-libs

Status
Aiohttp
Vendor
CVE Published:
13 November 2026

What is CVE-2026-128129?

The AIOHTTP framework, a popular asynchronous HTTP client/server for Python, has a significant vulnerability that allows a remote attacker to exploit unbounded memory consumption during a WebSocket upgrade request. When additional connection data is handled while the request is pending, the lack of size limits or flow control can lead to excessive memory usage. This vulnerability affects all versions prior to 3.14.4 and necessitates immediate upgrading to protect against potential Denial of Service attacks. Users can mitigate this risk by ensuring they are using the latest version 3.14.4 or above.

Affected Version(s)

aiohttp < 3.14.4

References

https://github.com/aio-libs/aiohttp/security/advisories/G...
x_refsource_CONFIRM
https://github.com/aio-libs/aiohttp/pull/13501
x_refsource_MISC
https://github.com/aio-libs/aiohttp/pull/13511
x_refsource_MISC

CVSS V4

Score:
8.2
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.