CVE-2026-27446
Description
A flaw was found in Apache Artemis and Apache ActiveMQ Artemis. An unauthenticated remote attacker can exploit a missing authentication for critical function vulnerability by using the Core protocol. This allows the attacker to force a target broker to establish an outbound Core federation connection to an attacker-controlled rogue broker. The primary consequence is the potential for message injection into any queue and/or message exfiltration from any queue via the rogue broker.
Statement
Red Hat rates this flaw as IMPORTANT severity because it does not enable remote code execution or system compromise (arbitrary code execution), which is Red Hat's threshold for Critical impact. Its impact is limited to message injection and exfiltration via rogue broker federation. Exploitation requires the broker to accept inbound Core protocol connections from untrusted networks with outbound connectivity to attacker-controlled systems. Availability impact is set to None as exploitation does not cause service disruption or broker instability.
Mitigation
To mitigate this issue, restrict Core protocol support on acceptors receiving connections from untrusted sources. The default "artemis" acceptor on port 61616 supports all protocols, including Core. Modify the acceptor URL to explicitly exclude the Core protocol using the "protocols" URL parameter. Alternatively, configure two-way SSL with certificate-based authentication to prevent unauthenticated exploitation. A service restart or reload may be required for changes to take effect.
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 | 9.1 | 9.8 | 9.1 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | None | High | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Understanding the Weakness (CWE)
Access Control,Other
Technical Impact: Gain Privileges or Assume Identity; Varies by Context
Exposing critical functionality essentially provides an attacker with the privilege level of that functionality. The consequences will depend on the associated functionality, but they can range from reading or modifying sensitive data, accessing administrative or other privileged functionality, or possibly even executing arbitrary code.
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