Apache Karaf up to 4.4.11 Instance Management InstanceServiceImpl javaOpts os command injection

Summaryinfo

A vulnerability was found in Apache Karaf up to 4.4.11. It has been rated as critical. This issue affects the function InstanceServiceImpl of the component Instance Management. This manipulation of the argument javaOpts causes os command injection. The identification of this vulnerability is CVE-2026-91006. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Apache Karaf up to 4.4.11. It has been declared as critical. Affected by this vulnerability is the function InstanceServiceImpl of the component Instance Management. The manipulation of the argument javaOpts with an unknown input leads to a os command injection vulnerability. The CWE definition for the vulnerability is CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Apache Karaf's instance-management service (InstanceServiceImpl) builds the command line used to launch a child Karaf JVM by string concatenation, then executes it through /bin/sh (Unix) or cscript (Windows). The caller-supplied javaOpts value is spliced into that string unquoted. A javaOpts value containing shell metacharacters (;, |, `, $(...)) is interpreted by the shell instead of being passed to the JVM as an option, giving arbitrary OS command execution as the Karaf process user. Reachable via the shell commands instance:create, instance:start, instance:restart, instance:change-opts, and the equivalent InstanceMBean JMX operations (createInstance, startInstance, changeJavaOpts, cloneInstance). Mitigation  * Set karaf.secured.command.compulsory.roles=admin in etc/system.properties to close the fail-open gap for all unconfigured command scopes. * Restrict which principals can reach instance:* commands and InstancesMBean via etc/users.properties role assignments. * Treat javaOpts passed to instance:create/instance:start/instance:change-opts/InstancesMBean as untrusted input only from fully-trusted operators.

It is possible to read the advisory at lists.apache.org. This vulnerability is known as CVE-2026-91006 since 09/14/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/28/2026). The attack technique deployed by this issue is T1202 according to MITRE ATT&CK.

Upgrading to version 4.4.12 eliminates this vulnerability.

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Productinfo

Vendor

• Apache

Name

• Karaf

Version

• 4.4.0
• 4.4.1
• 4.4.2
• 4.4.3
• 4.4.4
• 4.4.5
• 4.4.6
• 4.4.7
• 4.4.8
• 4.4.9
• 4.4.10
• 4.4.11

License

• open-source

Website

• Vendor: https://www.apache.org/

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