CVE-2026-1281256.3MediumCWE-1325

CVE-2026-128125: AIOHTTP: Unbounded cookie storage in client CookieJar

aio-libs · aiohttp

Affected: aio-libs aiohttp · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.5%probability of exploitation in the next 30 days

44th percentile

050100

Higher than 44% of scored CVEs

6.3MediumCVSS 4.0

LowMediumHighCrit.

DescriptionCVE.org

AIOHTTP 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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

aio-libs · aiohttp< 3.14.4

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Improperly Controlled Sequential Memory Allocation · Denial of Service
Vendor: aio-libs
Published: November 2026
Band: Unlikely (under 1%), November 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-128125 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.