External risk intelligence

Apache Karaf JDBC and JMS Commands Allow Privilege Escalation to RCE

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-91048

The vulnerability resides within the Karaf shell command interface. Accessing the shell typically requires prior authentication and is generally restricted to internal administrative or maintenance sessions rather than being exposed as a public-facing network service.

Halo Surface Signal: 2 out of 5 — less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A security issue has been identified in Apache Karaf's command processing that could allow unauthorized code execution. This vulnerability arises from how certain commands, specifically those related to JDBC and JMS, are handled when no explicit access rules are defined, potentially enabling privilege escalation.

Unauthorized users can run restricted commands.
Considered critical, needs business context.
Focus on confirming relevance and exposure.

Attack Path

How an attacker could exploit the issue

An attacker with authenticated shell access, even with limited privileges like the "viewer" role, can exploit this vulnerability. By leveraging the Karaf shell's command handling, they can execute `jdbc:*` commands that are not properly restricted by access control. This allows them to manipulate the configuration of JDBC data sources, and if a vulnerable JDBC driver is in use, it can lead to arbitrary code execution on the server.

Authenticated shell session required.
Execute unvalidated `jdbc:*` commands.
Arbitrary code execution.

Live Threat

Current exploitation, exposure, and threat context

An authenticated user with a viewer role in the Karaf shell could execute arbitrary code on the system. This is because the `jdbc:*` and `jms:*` shell commands lack proper access control rules, allowing any authenticated user to run them. These commands can then be used to store a malicious JDBC URL, which, when processed by certain JDBC drivers, can lead to arbitrary code execution, bypassing existing security measures.

System data and service behavior.
Malicious JDBC URL processing.
Arbitrary code execution.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in Karaf's command guard and JDBC/JMS command handling could allow unauthenticated or low-privileged users to achieve arbitrary code execution. Platform or infrastructure teams managing Karaf instances are likely responsible for addressing this. The first practical move is to identify all Karaf instances, confirm exposure of the shell interface, and assess the business criticality of affected systems before planning remediation.

Platform and infrastructure teams own remediation.
Verify shell access and JVM impact.
Plan risk-based maintenance or vendor coordination.

Supplementary metadata

CVSS vector

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Frequently asked questions

What is Apache Karaf and why is it used?

Apache Karaf is a modular, OSGi-based runtime platform that provides a container for applications and services. It is widely used to manage and deploy server-side software, offering built-in features like a remote shell interface for administrators to monitor, configure, and maintain the system's runtime environment.

How does CVE-2026-91048 work as a security weakness?

This vulnerability is classified as CWE-862, or Missing Authorization. In Apache Karaf, the system fails to verify permissions for JDBC and JMS shell commands when no specific access control rules are defined. Because of this gap, the shell interprets unauthorized requests as permitted, allowing users to perform sensitive actions they should not have the rights to execute.

Do I need to worry about this if I have no shell access?

No. The attack requires an already authenticated shell session. Simply having a user account on a broader system does not trigger this; the attacker must be able to log into the specific Karaf command shell interface. If you have no Karaf shell interface enabled or accessible, this specific trigger path is not available to an attacker.

Is my system at risk according to Halo Surface Signal?

Halo Surface Signal indicates that exploitation is unlikely for most because the Karaf shell interface is typically reserved for internal maintenance. Unless your specific instance exposes this administrative shell directly to the public internet, the practical barrier for an attacker is high because they must first overcome existing authentication requirements.

What is the first step to address this CVE?

Your priority is to inventory your environment to locate all running Apache Karaf instances. Once identified, confirm which instances have the shell interface enabled and who has access to them. Focus on systems with higher business criticality while coordinating with your infrastructure teams to assess how to secure or restrict the Karaf command environment.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.