CVE-2026-54278
Description
A flaw was found in aiohttp, an asynchronous HTTP client/server framework. An attacker could send a specially crafted compressed request body that, during cleanup, would be decompressed into memory in one large chunk. This could potentially lead to a Denial of Service (DoS) condition, where the affected system becomes unresponsive or unavailable.
Statement
This vulnerability is rated Moderate because an unauthenticated remote attacker can trigger denial of service against an affected aiohttp HTTP server by sending a compressed request body that is decompressed into memory in one large chunk during cleanup, bypassing client_max_size limits (a zip-bomb style edge case). Exploitation requires aiohttp deployed as a network-facing HTTP server that accepts compressed request bodies.
Many Red Hat products ship aiohttp as a bundled dependency for client libraries, internal automation, or services that do not expose this server path 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 directly to untrusted networks. As a workaround, disable HTTP request body compression on aiohttp servers if unable to upgrade immediately. Installations that use aiohttp only as an HTTP client 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: Amplification; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
System resources, CPU and memory, can be quickly consumed. This can lead to poor system performance or system crash.
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