CVE-2026-100656
Description
A flaw was found in Netty. This vulnerability allows a remote, unauthenticated attacker to cause a Denial of Service (DoS) by sending numerous pipelined HTTP/1.1 requests over a single connection while withholding reads. Netty's HTTP server codec stores unanswered requests in an internal queue without a size limit, leading to excessive memory consumption and an eventual application crash.
Statement
This vulnerability is rated as an Important severity flaw because an unauthenticated network attacker can trigger an application-wide denial of service through memory exhaustion without needing prior credentials or complex preconditions. In Red Hat environments, Netty is widely bundled as an underlying network engine across middleware and containerized offerings, including Red Hat Build of Keycloak, Quarkus, and JBoss EAP. When HTTP/1.1 services accept pipelined requests, a malicious client can continuously send incoming queries over an individual connection while intentionally pausing consumption of server responses, consuming system heap until the Java virtual machine crashes.
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 | 7.5 | N/A | 7.5 |
| 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 | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: 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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