CVE-2026-50734
Description
A flaw was found in Apache ActiveMQ. An unauthenticated network attacker can exploit this vulnerability by sending a specially crafted WireFormatInfo frame with an excessively large size value. This unvalidated value causes the broker to attempt an oversized memory allocation during pre-authentication negotiation. Consequently, this can lead to an Out Of Memory (OOM) error, resulting in a Denial of Service (DoS) and crashing the broker.
Statement
A flaw was found in Apache ActiveMQ Classic's OpenWire protocol handling. An unauthenticated remote attacker can crash the broker by sending a crafted WireFormatInfo frame with a malicious oversized value during pre-authentication protocol negotiation, causing an Out of Memory condition. Red Hat AMQ Broker is based on Apache ActiveMQ Artemis, but its OpenWire protocol support delegates wire format negotiation to Classic ActiveMQ's activemq-client code, which is vulnerable to this attack on the OpenWire listener port.
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 | 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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