CVE-2026-69244: CWE-400: Uncontrolled Resource Consumption in aio-libs aiohttp
CVE-2026-69244 is a high severity vulnerability in aiohttp, an asynchronous HTTP client/server framework for Python. Versions prior to 3.14.3 contain an out-of-bounds heap read in the C response parser during error message construction for malformed HTTP responses. This flaw can be triggered by a malicious or accidental server response, potentially causing a denial of service (DoS) in the client. The issue is fixed in version 3.14.3.
AI Analysis
Technical Summary
The vulnerability in aiohttp versions before 3.14.3 arises from an out-of-bounds heap read in the C response parser component, specifically in aiohttp/_http_parser.pyx. When processing malformed chunked responses or malformed request/response bytes at the buffer end, the error message construction uses an llhttp error-position pointer incorrectly, leading to uncontrolled resource consumption and a potential denial of service. This flaw is tracked as CWE-400 (Uncontrolled Resource Consumption), CWE-416 (Use After Free), and CWE-125 (Out-of-bounds Read). The vulnerability is resolved in aiohttp version 3.14.3.
Potential Impact
An attacker controlling a server or an accidental malformed response can trigger a denial of service in aiohttp clients by exploiting the out-of-bounds heap read during error message construction. This can cause the client application to crash or behave unexpectedly, impacting availability.
Mitigation Recommendations
Upgrade aiohttp to version 3.14.3 or later, where this vulnerability is fixed. There is no indication of alternative mitigations or temporary workarounds. Patch status is confirmed by the vendor advisory stating the fix is in 3.14.3.
CVE-2026-69244: CWE-400: Uncontrolled Resource Consumption in aio-libs aiohttp
Description
CVE-2026-69244 is a high severity vulnerability in aiohttp, an asynchronous HTTP client/server framework for Python. Versions prior to 3.14.3 contain an out-of-bounds heap read in the C response parser during error message construction for malformed HTTP responses. This flaw can be triggered by a malicious or accidental server response, potentially causing a denial of service (DoS) in the client. The issue is fixed in version 3.14.3.
CVSS v4.0
Score 7.1high
Affected software
aio-libs
aiohttp
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in aiohttp versions before 3.14.3 arises from an out-of-bounds heap read in the C response parser component, specifically in aiohttp/_http_parser.pyx. When processing malformed chunked responses or malformed request/response bytes at the buffer end, the error message construction uses an llhttp error-position pointer incorrectly, leading to uncontrolled resource consumption and a potential denial of service. This flaw is tracked as CWE-400 (Uncontrolled Resource Consumption), CWE-416 (Use After Free), and CWE-125 (Out-of-bounds Read). The vulnerability is resolved in aiohttp version 3.14.3.
Potential Impact
An attacker controlling a server or an accidental malformed response can trigger a denial of service in aiohttp clients by exploiting the out-of-bounds heap read during error message construction. This can cause the client application to crash or behave unexpectedly, impacting availability.
Mitigation Recommendations
Upgrade aiohttp to version 3.14.3 or later, where this vulnerability is fixed. There is no indication of alternative mitigations or temporary workarounds. Patch status is confirmed by the vendor advisory stating the fix is in 3.14.3.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-08-03T19:54:19.852Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a7105c1bf32cb7a3436d7ee
Added to database: 08/03/2026, 21:18:57 UTC
Last enriched: 08/11/2026, 18:37:45 UTC
Last updated: 09/17/2026, 22:01:37 UTC
Views: 52
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