CVE-2026-54273
Description
A flaw was found in AIOHTTP, an asynchronous HTTP client/server framework for asyncio and Python. An attacker could exploit this vulnerability by sending an unlimited number of pipelined requests, causing the system to consume excessive amounts of memory. This could lead to a Denial of Service (DoS), making the affected system unavailable to legitimate users.
Statement
This vulnerability is rated Moderate because an unauthenticated remote attacker can trigger denial of service against an affected aiohttp HTTP/1 server by sending a large number of pipelined requests, causing excessive memory consumption. Exploitation requires aiohttp to be deployed as an HTTP/1 server that accepts pipelined requests from untrusted clients.
Many Red Hat products ship aiohttp as a bundled dependency for client libraries, internal automation, or services that do not expose this server behavior to untrusted users. In those configurations, practical risk may be lower, but affected packages should still be updated to aiohttp 3.14.1 or later when fixes are released.
Mitigation
Update the aiohttp package to version 3.14.1 or later.
Until updated builds are available for a given product, reduce exposure by not exposing aiohttp-based HTTP/1 servers directly to untrusted networks. A reverse proxy in front of the service can help limit abusive pipelined request patterns. Installations that use aiohttp only as an HTTP client, or that do not accept HTTP/1 pipelined requests on an aiohttp server, are not affected by this flaw.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.9 | 7.5 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource. It can be easy for an attacker to consume many resources by rapidly making many requests or causing larger resources to be used than is needed.
Frequently Asked Questions
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