CVE-2026-49017
Description
A flaw was found in OpenStack Swift. An authenticated attacker can exploit this vulnerability by sending a specially crafted, truncated aws-chunked PUT request body to the s3api middleware. This action causes an infinite loop within the StreamingInput class, leading to the affected proxy-server worker becoming unresponsive. Consequently, an attacker can exhaust all available proxy-server workers, resulting in a Denial of Service (DoS) for the system.
Mitigation
If S3 API compatibility is not required, the `s3api` middleware can be disabled in the Swift proxy server configuration. This action will prevent the exploitation of this vulnerability by removing the affected functionality. Disabling `s3api` will remove S3 API support for OpenStack Swift, which may impact services relying on this functionality.
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 | 6.5 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/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: Amplification
An infinite loop will cause unexpected consumption of resources, such as CPU cycles or memory. The software's operation may slow down, or cause a long time to respond.
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