CVE-2026-47244
Description
A flaw was found in Netty, a network application framework. A remote attacker can exploit this vulnerability by sending a large number of HTTP/2 stream requests to a Netty HTTP/2 server. If the server does not explicitly limit concurrent streams, it can lead to the allocation of numerous long-lived stream objects. This excessive resource consumption can result in a denial of service (DoS), making the server unavailable to legitimate users.
Statement
This Moderate impact flaw in Netty's HTTP/2 implementation can lead to a denial of service in Red Hat products that utilize Netty as an HTTP/2 server without explicitly configured limits on concurrent streams. An attacker can exhaust server resources by initiating numerous HTTP/2 stream requests, rendering the service unavailable. The impact is limited to denial of service and requires a specific server configuration to be exploitable.
Mitigation
Configure affected applications using Netty HTTP/2 servers to explicitly set a maximum concurrent streams limit. Consult product-specific documentation for instructions on how to apply this configuration. Additionally, restrict network access to affected services to trusted clients and networks by implementing firewall rules or other network access controls. This may impact legitimate traffic if not carefully configured.
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).
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 | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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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