CVE-2026-54274
Description
A flaw was found in aiohttp, an asynchronous HTTP client/server framework. An attacker can exploit this vulnerability by sending large, incomplete websocket frame payloads. This can bypass normal memory usage limits, potentially leading to a Denial of Service (DoS) where the affected system becomes unavailable.
Statement
This vulnerability is rated Moderate because an unauthenticated remote attacker can trigger denial of service against an affected aiohttp HTTP server with WebSocket endpoints by sending large incomplete WebSocket frame payloads that bypass memory size limits.
Exploitation requires aiohttp deployed as a network-facing HTTP server that exposes WebSocket endpoints to untrusted clients. Many Red Hat products ship aiohttp as a bundled dependency for client libraries, internal automation, or services that do not expose WebSocket listeners 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, reduce exposure by not exposing aiohttp-based HTTP servers with WebSocket endpoints directly to untrusted networks. A reverse proxy or load balancer in front of the service can help limit abusive WebSocket traffic. Installations that use aiohttp only as an HTTP client, or that do not expose WebSocket endpoints, 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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