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Fencer Vulns
medium 5.3

CVE-2025-69229 json

AIOHTTP vulnerable to DoS through chunked messages

published 2026-01-05 10 mo ago modified 2026-10-11 28 d ago also EUVD-2026-1043 , GHSA-g84x-mcqj-x9qq , PYSEC-2026-1106

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. In versions 3.13.2 and below, handling of chunked messages can result in excessive blocking CPU usage when receiving a large number of chunks. If an application makes use of the request.read() method in an endpoint, it may be possible for an attacker to cause the server to spend a moderate amount of blocking CPU time (e.g. 1 second) while processing the request. This could potentially lead to DoS as the server would be unable to handle other requests during that time. This issue is fixed in version 3.13.3.

Patch / fix

  • pypi aiohttp 3.13.3
  • aiohttp aiohttp 3.13.3
  • python-aiohttp Debian 12 3.8.4-1+deb12u2
  • python-aiohttp Debian 13 3.11.16-1+deb13u1
  • python-aiohttp Debian 14 3.13.3-1

debian advisories DEBIAN-CVE-2025-69229

  • python-aiohttp Ubuntu 25.10 3.11.16-1ubuntu0.1
  • python-aiohttp Ubuntu Pro 18.04 LTS 3.0.1-1ubuntu0.1~esm6
  • python-aiohttp Ubuntu Pro 22.04 LTS 3.8.1-4ubuntu0.2+esm2
  • python-aiohttp Ubuntu Pro 24.04 LTS 3.9.1-1ubuntu0.1+esm2

ubuntu advisories UBUNTU-CVE-2025-69229

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python-aiohttp SLE Module for Public Cloud 15 SP7, SLE Module for Public Cloud 15 SP6, SLE Module for Public Cloud 15 SP5 +1 more 3.6.0-150100.3.32.1
  • python-aiohttp SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +10 more 3.9.3-150400.10.36.1
  • python-Brotli SLES for SAP applications 16.0, SLES 16.0 1.1.0-160000.3.1
  • python-aiohttp SLES for SAP applications 16.0, SLES 16.0 3.11.16-160000.3.1

suse advisories SUSE-SU-2026:0859-1SUSE-SU-2026:0858-1SUSE-SU-2026:20425-1

  • python-Brotli openSUSE Leap 16.0 1.1.0-160000.3.1
  • python-aiohttp openSUSE Leap 16.0 3.11.16-160000.3.1
  • python-aiohttp openSUSE Tumbleweed 3.13.3-1.1

opensuse advisories openSUSE-SU-2026:20204-1openSUSE-SU-2026:10025-1

  • py3-aiohttp Alpine 3.24, Alpine 3.23 3.13.3-r0

alpine advisories ALPINE-CVE-2025-69229

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-69229 updated cvss 5.8

aiohttp: AIOHTTP: Denial of Service via excessive CPU usage in chunked message handling

  • Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-hook-runner-rhel8 Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-ocp-rag-rhel9, openshift-lightspeed/lightspeed-service-api-rhel9, openshift-lightspeed-tech-preview/lightspeed-rag-tool-rhel9 Red Hat OpenShift Service Mesh 2 openshift-service-mesh/pilot-rhel8, openshift-service-mesh/grafana-rhel8, openshift-service-mesh/proxyv2-rhel9, openshift-service-mesh/istio-cni-rhel8, openshift-service-mesh/ratelimit-rhel8, openshift-service-mesh/istio-rhel8-operator, +2 more Red Hat AI Inference Server rhaiis/vllm-tpu-rhel9, rhaiis/vllm-cuda-rhel9, rhaiis/vllm-rocm-rhel9, rhaiis/vllm-spyre-rhel9, rhaiis/model-opt-cuda-rhel9, rhaiis-preview/vllm-cuda-rhel9 Red Hat Ansible Automation Platform 2 automation-controller, ansible-automation-platform-24/hub-rhel8, ansible-automation-platform-25/hub-rhel8, ansible-automation-platform-26/hub-rhel9, ansible-automation-platform/ee-minimal-rhel8, ansible-automation-platform/ee-minimal-rhel9, +38 more Red Hat Ansible Automation Platform Ansible Core 2 ansible-automation-platform/ee-minimal-rhel8, ansible-automation-platform/ee-minimal-rhel9, ansible-automation-platform-tech-preview/ee-minimal-rhel8, ansible-automation-platform-tech-preview/ee-minimal-rhel9
    +3 more products
    Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-aws-cuda-rhel9, rhelai3/bootc-gcp-cuda-rhel9, rhelai3/bootc-azure-cuda-rhel9 Red Hat OpenShift AI (RHOAI) rhoai/odh-vllm-cpu-rhel9, rhoai/odh-vllm-cuda-rhel9, rhoai/odh-vllm-rocm-rhel9, rhoai/odh-caikit-nlp-rhel9, rhoai/odh-vllm-gaudi-rhel9, rhoai/odh-ta-lmes-job-rhel9, +36 more Red Hat Satellite 6 satellite/iop-insights-engine-rhel9, satellite/iop-vulnerability-engine-rhel9
    affected: workaround, no fix available “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
10 mo ago

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 6.6 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
CNA 4.0 6.6 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/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
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem package affected fixed in
pypi aiohttp
<3.13.3
3.13.3

Affected products

  • aio-libs aiohttp

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.