Cyber Resilience

CVE-2025-69229

DoS in Aiohttp ≤ 3.13.3

Published
06 January 2026
Modified
13 February 2026
Patch / advisory
CVSS Score v4 6.6
Click a component to see what it means
Raw vectorCVSS: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
EPSS Score 0.0034 26th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-69229 is a medium-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Aiohttp Aiohttp. Its CVSS base score is 6.6 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 26th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-5 (Denial-of-service Protection) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

CVE enables Endpoint DoS via application exploitation of chunked transfer handling (CWE-770 resource exhaustion).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-69228Same product: Aiohttp Aiohttp
CVE-2026-54277Same product: Aiohttp Aiohttp
CVE-2026-34517Same product: Aiohttp Aiohttp
CVE-2026-34513Same product: Aiohttp Aiohttp
CVE-2026-34516Same product: Aiohttp Aiohttp
CVE-2026-22815Same product: Aiohttp Aiohttp
CVE-2026-54274Same product: Aiohttp Aiohttp
CVE-2026-54280Same product: Aiohttp Aiohttp
CVE-2025-69223Same product: Aiohttp Aiohttp
CVE-2026-54278Same product: Aiohttp Aiohttp

Affected Assets

aiohttp
aiohttp
≤ 3.13.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SC-5 Denial-of-service Protection
  • SI-10 Information Input Validation
Detect
Catch it (NIST detect / respond)
  • SI-4 System Monitoring
Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V15.4.4

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires protection against DoS via resource exhaustion from unbounded chunked HTTP input.

prevent

Enforces validation and limits on incoming request data (chunk count/size) before request.read() processing.

detect

Enables monitoring of CPU usage and anomalous request patterns that indicate chunk-induced blocking.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.IR-04 mostly match
degrades

Monitoring capacity and taking action to maintain availability directly reduces unchecked resource allocation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Baseline comparison of CPU, memory and bandwidth usage helps surface uncontrolled resource allocations before they cause service degradation.

prevents

Capacity projections and elasticity measures ensure that allocation requests are bounded and can be throttled, reducing the window in which an attacker can force unbounded resource reservations.

mitigates

Defining retention periods and deletion schedules for backup copies prevents indefinite accumulation of data on storage media without corresponding resource-management controls.

mitigates

Architectural redundancy and automatic failover limit the impact of an attacker who forces excessive allocations, because spare capacity can absorb the load until the primary instance recovers.

none

Documented incident response procedures that include activation of continuity plans and controlled recovery help ensure that resource consumption triggered by an incident is bounded and managed rather than left unbounded.

none

Mandating tested continuity procedures that preserve or replace resource-limiting controls prevents an attacker from exploiting the absence of throttling mechanisms during an outage.

References