CVE-2026-91085 Apache Karaf: config:install missing ACL entry allows privilege escalation to admin
Missing ACL entry for config:install allows low-privilege users to overwrite security files, leading to privilege escalation and potential code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-91085?
CVE-2026-91085 is a medium-severity missing authorization vulnerability in Apache Karaf, published on 29 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Apache Karaf's shell/SSH command security is enforced by per-scope ACL configuration files (etc/org.apache.karaf.command.acl.<scope>.cfg). SecuredSessionFactoryImpl.checkSecurity() resolves the roles required for an invocation and, when no ACL rule matches the command, fails open: ACLConfigurationParser.Specificity.NO_MATCH sets passCheck = true. The safety valve for this, karaf.secured.command.compulsory.roles, ships commented out in etc/system.properties, so an unmatched command is allowed for any authenticated user.
The shipped org.apache.karaf.command.acl.config ACL (assemblies/features/standard/src/main/feature/feature.xml, mirrored into instance/.../etc/org.apache.karaf.command.acl.config.cfg) has no install entry. It restricts delete to admin, restricts edit/property-*/update on the jmx.acl.*, org.apache.karaf.command.acl.* and org.apache.karaf.service.acl.* PIDs to admin, and allows manager for everything else, but config:install was simply unmatched, and therefore allowed for any authenticated user, including one holding only the viewer role.
config:install <url> <finalname> fetches url and writes it into ${karaf.etc} as finalname. It calls PathUtils.checkWithin() to block .. traversal outside karaf.etc, but that folder holds every security-relevant file Karaf ships: users.properties, keys.properties, host.key, and all org.apache.karaf.*.acl.* files, including the very ACL file that (mis)governs this command. With -o/--override, an existing file is overwritten with attacker-controlled bytes fetched from an arbitrary URL.
Because felix.fileinstall.dir = ${karaf.etc} (etc/config.properties), Felix FileInstall also watches and reloads any .cfg file dropped there, closing the loop without requiring a restart.
By contrast, bundle:install, feature:install and kar:install are all admin-only in their own ACLs, and config:delete is admin in this same ACL, config:install was the outlier.
MitigationAdd install = admin in etc/org.apache.karaf.command.acl.config.cfg (create the file is absent), and/or set karaf.secured.command.compulsory.roles=admin in etc/system.properties (and restart) to make unmatched commands fail closed by default.
Weakness: CWE-862
Which versions are affected by CVE-2026-91085?
It affects 1 product.
Products include Apache Karaf.
How do I fix CVE-2026-91085?
No fix has been published for CVE-2026-91085 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-91085 being exploited?
There is no known exploitation of CVE-2026-91085 in the wild and no public exploit code.
Other vulnerabilities in Apache Karaf
- CVE-2026-91012 Apache Karaf: Path Traversal in Config Service Allows Manager-to-Admin Privilege Escalation
- CVE-2026-91048 Missing authorization in Apache Karaf
- CVE-2022-40145 Apache Karaf: JDBC JAAS LDAP injection
- CVE-2018-11788 XML External Entity Reference in Apache Karaf
- CVE-2026-92142 Apache Karaf: Authorization bypass in JMX MBean lifecycle operations
Sources
Also known as GHSA-8g53-m82p-xqf5.