Medium severity · published Sep 29, 2026
CVE-2026-91085
Apache Karaf: config:install missing ACL entry allows privilege escalation to admin
6.3
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AK
Apache Karaf · Apache Software Foundation
before 4.4.12 · source: vendor
KA
Karaf · Apache
before 4.4.12 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91085
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-91085
vendor-advisory
https://karaf.apache.org/security/cve-2026-91085.txt
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