AIOHTTP: Pure-Python parser request replay and buffer growth behind a declined upgrade

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-128130
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-11-13 21:17:44 UTC
Updated2026-11-13 22:11:32 UTC
DescriptionAIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, when the pipelined request queue is full, the pure-Python parser stores the unparsed remainder internally and also returns the same data to its caller. After a handler declines an upgrade request, the caller feeds the remainder back to the parser, causing the buffer to grow with each handled request and dispatching already-handled requests to the application again. The issue affects deployments using AIOHTTP_NO_EXTENSIONS or otherwise running without the standard C-extension wheel, and can cause excessive memory use and repeated request processing. This issue is fixed in version 3.14.4.

Risk And Classification

Primary CVSS: v4.0 8.3 HIGH from [email protected]

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Problem Types: CWE-770 | CWE-835 | CWE-770 CWE-770: Allocation of Resources Without Limits or Throttling | CWE-835 CWE-835: Loop with Unreachable Exit Condition

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary8.3HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/C...
4.0CNADECLARED8.3HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
Low
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Aio-libs Aiohttp affected < 3.14.4 Not specified

References

ReferenceSourceLinkTags
github.com/aio-libs/aiohttp/commit/72eaa429cf89b1e20212590f3e704444239569fb [email protected] github.com
github.com/aio-libs/aiohttp/pull/13356 [email protected] github.com
github.com/aio-libs/aiohttp/releases/tag/v3.14.4 [email protected] github.com
github.com/aio-libs/aiohttp/pull/13360 [email protected] github.com
github.com/aio-libs/aiohttp/security/advisories/GHSA-28qf-cpwq-vmc2 [email protected] github.com
github.com/aio-libs/aiohttp/commit/47babd8c23ca79e2bae6cc8dcb5752b61e369fc7 [email protected] github.com
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