CVE-2026-126071
Description
A flaw was found in the Active Storage component of Ruby on Rails. When files are served using proxy streaming, an error from the underlying cloud storage service partway through a download fails to properly close the streaming buffer. As a result, the server thread handling the request remains blocked until the application process restarts. A remote attacker can exploit this flaw by repeatedly triggering failed or interrupted downloads to exhaust server worker threads, leading to a Denial of Service (DoS).
Statement
This vulnerability is rated as having a Moderate impact for Red Hat because successful exploitation requires specific environmental preconditions and timing rather than enabling unauthorized data access or code execution. In affected environments, worker threads become unresponsive only when backend storage interruptions or file removals occur midway through an active file stream. Consequently, sustained denial of service requires repeatedly provoking mid-transfer failures across multiple server threads.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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 | 5.3 | N/A | 5.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (Other); DoS: Resource Consumption (Memory); DoS: Resource Consumption (CPU)
An attacker that can influence the allocation of resources that are not properly released could deplete the available resource pool and prevent all other processes from accessing the same type of resource. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.
Frequently Asked Questions
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