{"id":"CVE-2026-100252","aliases":["DEBIAN-CVE-2026-100252","EUVD-2026-116867","GHSA-f6p9-rj89-vgmr","UBUNTU-CVE-2026-100252"],"status":"published","title":"Apache ZooKeeper: SASL authorization bypass on the client port through a client-supplied authorization ID","description":"Improper Authorization vulnerability in Apache ZooKeeper.\n\nWhen 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.\n\nAn 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.\n\nUsers are recommended to upgrade to version 3.8.8 or 3.9.7, which fixes the issue.","severity":{"version":"4.0","score":8.6,"vector":"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00532,"percentile":0.45326,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-863"],"published":"2026-11-04T10:44:17Z","modified":"2026-11-06T15:01:04Z","affected":[{"source":"osv","ecosystem":"Debian:12","package":"zookeeper","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"]},{"source":"osv","ecosystem":"Debian:13","package":"zookeeper","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"]},{"source":"osv","ecosystem":"Debian:14","package":"zookeeper","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"]},{"source":"osv","ecosystem":"Ubuntu:Pro:14.04:LTS","package":"zookeeper","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"]},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"zookeeper","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"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"zookeeper","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"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"zookeeper","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"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"zookeeper","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"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"zookeeper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.8.0-11","3.9.1-1","3.9.1-1build1","3.9.1-1build2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"zookeeper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.9.5-1","3.9.5-2"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"zookeeper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.9.3-1build2","3.9.3-1build3","3.9.4-1","3.9.5-1"]}],"products":[{"vendor":"apache software foundation","product":"apache zookeeper"}],"references":[{"url":"https://lists.apache.org/thread.html/81rdyqlmlp3dtkkqgp8t5080g3b9r2pj","tags":["vendor-advisory","report"]},{"url":"http://www.openwall.com/lists/oss-security/2026/11/03/10","tags":["report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-100252"},{"url":"https://github.com/advisories/GHSA-f6p9-rj89-vgmr"},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-100252","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-100252","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-100252","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-100252","title":"Apache ZooKeeper: SASL authorization bypass on the client port through a client-supplied authorization ID","description":"Improper Authorization vulnerability in Apache ZooKeeper.\n\nWhen 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.\n\nAn 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.\n\nUsers are recommended to upgrade to version 3.8.8 or 3.9.7, which fixes the issue.","status":"published","published":"2026-11-04T10:44:17.367Z","modified":"2026-11-05T04:55:52.687Z","cvss":[{"version":"4.0","score":8.6,"vector":"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","level":"high","assessor":"cna"}],"cwes":["CWE-863"],"updated_at":"2026-11-05T06:56:15.67765Z"}],"euvd":[{"id":"EUVD-2026-116867","description":"Improper Authorization vulnerability in Apache ZooKeeper.\n\nWhen 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.\n\nAn 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.\n\nUsers are recommended to upgrade to version 3.8.8 or 3.9.7, which fixes the issue.","status":"published","published":"2026-11-04T10:44:17Z","modified":"2026-11-05T04:55:52Z","cvss":[{"version":"4.0","score":8.6,"vector":"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","level":"high"}],"updated_at":"2026-11-05T06:54:33.955364Z"}],"ghsa":[{"id":"GHSA-f6p9-rj89-vgmr","title":"Improper Authorization vulnerability in Apache ZooKeeper.\n\nWhen SASL authentication is enabled on...","description":"Improper Authorization vulnerability in Apache ZooKeeper.\n\nWhen 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.\n\nAn 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.\n\nUsers are recommended to upgrade to version 3.8.8 or 3.9.7, which fixes the issue.","status":"published","published":"2026-11-04T12:31:30Z","modified":"2026-11-04T12:31:38Z","cvss":[{"version":"4.0","score":8.6,"vector":"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","level":"high"}],"cwes":["CWE-863"],"updated_at":"2026-11-04T12:34:56.311878Z"}],"nvd":[{"id":"CVE-2026-100252","description":"Improper Authorization vulnerability in Apache ZooKeeper.\n\nWhen 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.\n\nAn 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.\n\nUsers are recommended to upgrade to version 3.8.8 or 3.9.7, which fixes the issue.","status":"published","published":"2026-11-04T11:17:06.717Z","modified":"2026-11-05T05:18:18.29Z","cvss":[{"version":"4.0","score":8.6,"vector":"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","level":"high","assessor":"secondary"}],"cwes":["CWE-863"],"updated_at":"2026-11-05T06:56:53.90913Z"}],"osv":[{"id":"DEBIAN-CVE-2026-100252","description":"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.","status":"published","published":"2026-11-04T11:17:06.717Z","modified":"2026-11-06T15:01:04.718951742Z","cvss":[{"version":"4.0","score":8.6,"vector":"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","level":"high"}],"updated_at":"2026-11-06T15:27:36.398977Z"},{"id":"UBUNTU-CVE-2026-100252","description":"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.","status":"published","published":"2026-11-05T00:00:00Z","modified":"2026-11-06T01:00:17.388722304Z","cvss":[{"version":"4.0","score":8.6,"vector":"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","level":"high"}],"updated_at":"2026-11-06T01:33:11.614208Z"}]}}