CVE-2026-91006
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.
- Score
- CVSS 3.1 8.8 High
- Status
- Analyzed - security@apache.org
- Published
- 2026-09-28
- Last modified
- 2026-10-08
- Weaknesses
- CWE-78
Affected products
References
- https://lists.apache.org/thread/olzy0yjw82b20w59vonfjr1x7v5yzocr
- http://www.openwall.com/lists/oss-security/2026/09/28/3