AIOHTTP: Unbounded cookie storage in client CookieJar

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-128125
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-11-13 21:17:44 UTC
Updated2026-11-13 22:17:23 UTC
DescriptionAIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Set-Cookie parsing treats unrecognized name=value attributes as additional cookies, while CookieJar does not limit the number of cookies stored or sent. A malicious server can make an aiohttp client accumulate a very large cookie set, consume memory and CPU repeatedly across redirects, and construct an excessively large Cookie header for later requests to the same domain. This issue is fixed in version 3.14.4.

Risk And Classification

Primary CVSS: v4.0 6.3 MEDIUM from [email protected]

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/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-1325 | CWE-1325 CWE-1325: Improperly Controlled Sequential Memory Allocation

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary6.3MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/C...
4.0CNADECLARED6.3MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/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
None
Availability
Low
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:N/VA:L/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/security/advisories/GHSA-5pv8-vvhc-h7jv [email protected] github.com
github.com/aio-libs/aiohttp/commit/6963ee0befec1502b6bb7b4db6c72d044c08f4fa [email protected] github.com
github.com/aio-libs/aiohttp/releases/tag/v3.14.4 [email protected] github.com
github.com/aio-libs/aiohttp/pull/13930 [email protected] github.com
github.com/aio-libs/aiohttp/commit/b1f6c87b2bd3bd80f2b6c22ff46e11d00921e412 [email protected] github.com
github.com/aio-libs/aiohttp/pull/13942 [email protected] github.com
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