{"id":"DEBIAN-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":"2026-11-06T15:01:04.718951742Z","published":"2026-11-04T11:17:06.717Z","upstream":["CVE-2026-100252"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-100252"}],"affected":[{"package":{"name":"zookeeper","ecosystem":"Debian:12","purl":"pkg:deb/debian/zookeeper?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.8.0-11","3.8.0-11+deb12u1","3.8.0-11+deb12u2","3.9.1-1","3.9.2-1","3.9.2-2","3.9.3-1","3.9.3-2","3.9.4-1","3.9.4-2","3.9.5-1","3.9.5-2","3.9.6-1","3.9.6-2","3.9.6-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-100252.json"}},{"package":{"name":"zookeeper","ecosystem":"Debian:13","purl":"pkg:deb/debian/zookeeper?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.9.3-1","3.9.3-1+deb13u1","3.9.3-2","3.9.4-1","3.9.4-2","3.9.5-1","3.9.5-2","3.9.6-1","3.9.6-2","3.9.6-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-100252.json"}},{"package":{"name":"zookeeper","ecosystem":"Debian:14","purl":"pkg:deb/debian/zookeeper?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.9.3-1","3.9.3-2","3.9.4-1","3.9.4-2","3.9.5-1","3.9.5-2","3.9.6-1","3.9.6-2","3.9.6-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-100252.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}