{"id":"CVE-2026-59739","title":"Information disclosure via SetWatches reconnect replay in Apache ZooKeeper due to missing ACL check. An attacker can discover ACL-restricted paths by registering exists-watches on non-existent paths, then reconnecting after the paths are…","summary":"Information disclosure via SetWatches reconnect replay in Apache ZooKeeper due to missing ACL check. An attacker can discover ACL-restricted paths by registering exists-watches on non-existent paths, then reconnecting after the paths are…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cwe":["CWE-862","CWE-425"],"vendor":"apache","product":"zookeeper","affected":["zookeeper >= 3.8.0, < 3.8.7","zookeeper >= 3.9.0, < 3.9.6"],"patched":["zookeeper 3.9.6"],"published":"2026-09-16","updated":"2026-09-18","sourceUpdated":"2026-09-18T14:37:10.223","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-59739","references":[{"url":"https://lists.apache.org/thread/v0lrwsbdxvx6w67p3z7fxf3hzyncq55l","label":"security@apache.org"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-59739.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-59739"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2535093"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-59739"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59739"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00553,"epssPercentile":0.4599,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-17T19:17:33.790349Z"},"ingestedAt":"2026-09-16T09:53:11.603Z","scores":{"nvd":7.5,"vendor":6.5},"slug":"CVE-2026-59739","body":"## Overview\n\nInformation disclosure via SetWatches reconnect replay in Apache ZooKeeper due to missing ACL check. An attacker can discover ACL-restricted paths by registering exists-watches on non-existent paths, then reconnecting after the paths are created with restricted ACLs. Issue is caused by incomplete fix for CVE-2024-23944 (ZOOKEEPER-4799). The fix added ACL checking to WatchManager.triggerWatch(). However, DataTree.setWatches() — the SetWatches/SetWatches2 reconnect replay handler — still calls watcher.process(event) with null ACL, bypassing the check entirely. It's important to note that only the path is exposed by this vulnerability, not the data of znode, but since znode path can contain sensitive information like user name or login ID, this issue is potentially critical.\n\nUsers are recommended to upgrade to version 3.9.6, 3.8.7 which fixes the issue.\n\n## Affected\n\n- `zookeeper >= 3.8.0, < 3.8.7`\n- `zookeeper >= 3.9.0, < 3.9.6`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `zookeeper 3.9.6`\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat AMQ Broker 7, Red Hat build of Apache Camel 4 for Quarkus 3, Red Hat build of Apache Camel for Spring Boot 4, Red Hat Fuse 7, Red Hat JBoss Enterprise Application Platform 8, Red Hat JBoss Enterprise Application Platform Expansion Pack, … · no fix planned: Red Hat AMQ Broker 7, Red Hat build of Apache Camel 4 for Quarkus 3, Red Hat build of Apache Camel for Spring Boot 4, Red Hat Fuse 7, … · updated 2026-09-28 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-59739.json)","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":206556,"id":"CVE-2026-59739","ts":1789676927473,"field":"cvss","old":null,"new":"7.5"},{"seq":206555,"id":"CVE-2026-59739","ts":1789676927473,"field":"severity","old":"none","new":"high"}]}