{"id":"UBUNTU-CVE-2026-100252","details":"Improper Authorization vulnerability in Apache ZooKeeper. When SASL authentication is enabled on the client port, the server's SASL callback handler grants every authorization identity (authzid) that a client requests, without checking it against the principal the client authenticated as. The server then tries to replace the requested identity with a canonical form of the authenticated principal, derived from the zookeeper.security.auth_to_local rules. If no rule applies to the principal, canonicalization fails and the error is only logged. The client-requested authzid then becomes the session's SASL identity for all ACL checks. An authenticated client whose principal is not covered by the auth_to_local rules can therefore claim any SASL identity. With the default rules, this includes any Kerberos principal from a realm other than the server's default realm, such as a principal from a cross-realm trusted realm. The client then gets the permissions granted to that identity in sasl ACLs. If the requested identity matches a configured zookeeper.superUser, it gets superuser access to the whole data tree. Users are recommended to upgrade to version 3.8.8 or 3.9.7, which fixes the issue.","modified":"2026-11-06T01:00:17.388722304Z","published":"2026-11-05T00:00:00Z","upstream":["CVE-2026-100252"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-100252"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-100252"},{"type":"REPORT","url":"https://lists.apache.org/thread.html/81rdyqlmlp3dtkkqgp8t5080g3b9r2pj"},{"type":"REPORT","url":"http://www.openwall.com/lists/oss-security/2026/11/03/10"}],"affected":[{"package":{"name":"zookeeper","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/zookeeper?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.5+dfsg-1","3.4.5+dfsg-1ubuntu0.1~esm1","3.4.5+dfsg-1ubuntu0.1~esm3"],"ecosystem_specific":{"binaries":[{"binary_name":"libzookeeper-java","binary_version":"3.4.5+dfsg-1ubuntu0.1~esm3"},{"binary_name":"libzookeeper-mt2","binary_version":"3.4.5+dfsg-1ubuntu0.1~esm3"},{"binary_name":"libzookeeper-st2","binary_version":"3.4.5+dfsg-1ubuntu0.1~esm3"},{"binary_name":"libzookeeper2","binary_version":"3.4.5+dfsg-1ubuntu0.1~esm3"},{"binary_name":"python-zookeeper","binary_version":"3.4.5+dfsg-1ubuntu0.1~esm3"},{"binary_name":"zookeeper","binary_version":"3.4.5+dfsg-1ubuntu0.1~esm3"},{"binary_version":"3.4.5+dfsg-1ubuntu0.1~esm3","binary_name":"zookeeper-bin"},{"binary_name":"zookeeperd","binary_version":"3.4.5+dfsg-1ubuntu0.1~esm3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100252.json"}},{"package":{"name":"zookeeper","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/zookeeper?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.6-8","3.4.7-1","3.4.8-1","3.4.8-1ubuntu0.1~esm1","3.4.8-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"libzookeeper-java","binary_version":"3.4.8-1ubuntu0.1~esm2"},{"binary_name":"libzookeeper-mt2","binary_version":"3.4.8-1ubuntu0.1~esm2"},{"binary_version":"3.4.8-1ubuntu0.1~esm2","binary_name":"libzookeeper-st2"},{"binary_version":"3.4.8-1ubuntu0.1~esm2","binary_name":"libzookeeper2"},{"binary_name":"python-zookeeper","binary_version":"3.4.8-1ubuntu0.1~esm2"},{"binary_name":"zookeeper","binary_version":"3.4.8-1ubuntu0.1~esm2"},{"binary_name":"zookeeper-bin","binary_version":"3.4.8-1ubuntu0.1~esm2"},{"binary_version":"3.4.8-1ubuntu0.1~esm2","binary_name":"zookeeperd"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100252.json"}},{"package":{"name":"zookeeper","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/zookeeper?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.10-2","3.4.10-3","3.4.13-3","3.4.13-3ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libzookeeper-java","binary_version":"3.4.13-3ubuntu0.1~esm1"},{"binary_name":"libzookeeper-mt2","binary_version":"3.4.13-3ubuntu0.1~esm1"},{"binary_name":"libzookeeper-st2","binary_version":"3.4.13-3ubuntu0.1~esm1"},{"binary_name":"python-zookeeper","binary_version":"3.4.13-3ubuntu0.1~esm1"},{"binary_name":"zookeeper","binary_version":"3.4.13-3ubuntu0.1~esm1"},{"binary_name":"zookeeper-bin","binary_version":"3.4.13-3ubuntu0.1~esm1"},{"binary_version":"3.4.13-3ubuntu0.1~esm1","binary_name":"zookeeperd"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100252.json"}},{"package":{"name":"zookeeper","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/zookeeper?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.13-1","3.4.13-3","3.4.13-3build1","3.4.13-4","3.4.13-5","3.4.13-5build1","3.4.13-5ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libzookeeper-java","binary_version":"3.4.13-5ubuntu0.1"},{"binary_name":"libzookeeper-mt2","binary_version":"3.4.13-5ubuntu0.1"},{"binary_name":"libzookeeper-st2","binary_version":"3.4.13-5ubuntu0.1"},{"binary_name":"python3-zookeeper","binary_version":"3.4.13-5ubuntu0.1"},{"binary_version":"3.4.13-5ubuntu0.1","binary_name":"zookeeper"},{"binary_name":"zookeeper-bin","binary_version":"3.4.13-5ubuntu0.1"},{"binary_name":"zookeeperd","binary_version":"3.4.13-5ubuntu0.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100252.json"}},{"package":{"name":"zookeeper","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/zookeeper?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.13-5ubuntu4","3.4.13-6ubuntu2","3.4.13-6ubuntu3","3.4.13-6ubuntu4","3.4.13-6ubuntu4.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libzookeeper-java","binary_version":"3.4.13-6ubuntu4.1"},{"binary_name":"libzookeeper-mt2","binary_version":"3.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