aio-libs aiohttp up to 3.14.3 WebSocket Handshake memory allocation

CVSS Meta Temp Score
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CTI Interest Score
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4.1$0-$5k0.00+

Summaryinfo

A vulnerability was found in aio-libs aiohttp up to 3.14.3 and classified as problematic. The affected element is an unknown function of the component WebSocket Handshake. The manipulation results in memory allocation. This vulnerability is reported as CVE-2026-128129. The attack can be launched remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in aio-libs aiohttp up to 3.14.3. Affected is an unknown code of the component WebSocket Handshake. The manipulation with an unknown input leads to a memory allocation vulnerability. CWE is classifying the issue as CWE-789. The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. This is going to have an impact on availability. CVE summarizes:

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, aiohttp buffers all additional connection data received while a request marked for upgrade, such as a WebSocket handshake, is being handled, without a size limit or flow control. A remote attacker can stream data behind an upgrade request to a handler that does not immediately accept or reject the upgrade and cause unbounded memory consumption. This issue is fixed in version 3.14.4.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-128129 since 11/12/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The technical details are unknown and an exploit is not available.

Upgrading to version 3.14.4 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

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Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.1

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory allocation
CWE: CWE-789 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: aiohttp 3.14.4

Timelineinfo

11/12/2026 CVE reserved
11/13/2026 +1 days Advisory disclosed
11/13/2026 +0 days VulDB entry created
11/13/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CNA: GitHub_M
CVE: CVE-2026-128129 (🔒)

GCVE (CVE): GCVE-0-2026-128129
GCVE (VulDB): GCVE-100-437322

Entryinfo

Created: 11/13/2026 22:01
Changes: 11/13/2026 22:01 (67)
Complete: 🔍
Cache ID: 216::103

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