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CVE-2026-59739

Apache ZooKeeper: Information disclosure via SetWatches reconnect replay

Published: Sep 16, 2026Updated: Sep 18, 2026 Sources: CVE List NVDCWE-862
7.5HIGH
NVD MITRE
EPSS Score
0.6%
Top 54.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Not available

Description

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 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. Users are recommended to upgrade to version 3.9.6, 3.8.7 which fixes the issue.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:HI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:NIntegrity
None
A:NAvailability
None
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Weaknesses

CWE-862

Affected Products

Apache Software Foundation
oss-project·USaka apache foundation
Apache ZooKeeperOn-premWeb App
Databases / cache-message-queue
apache
oss-project·USaka apache http server, apache httpd
zookeeperOn-premDatabase
Databases / cache-message-queue

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Initial Access
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References

https://lists.apache.org/thread/v0lrwsbdxvx6w67p3z7fxf3hzyncq55l
lists.apache.org

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