Every CVE Search/ Get API key

CVE-2026-59739

Apache ZooKeeper: Information disclosure via SetWatches reconnect replay

7.5 HighFix available

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.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
High
Integrity
None
Availability
None

Exploit likelihood

0.55%Up 0.4 points since Sep 16, 2026
90%50%10%1%

What each source reports

CVE List Score used 7.5

Apache ZooKeeper: Information disclosure via SetWatches reconnect replay

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.

Record
CVE-2026-59739
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness
CWE-862
Updated
2026-11-02
EUVDEUVD-2026-80330 7.5

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.

Record
EUVD-2026-80330
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Updated
2026-11-02
GitHub AdvisoriesGHSA-wrgg-c9rw-j78f 7.5

Information disclosure via SetWatches reconnect replay in Apache ZooKeeper due to missing ACL...

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.

Record
GHSA-wrgg-c9rw-j78f
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness
CWE-862
Updated
2026-11-02
NVD 7.5

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.

Record
CVE-2026-59739
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness
CWE-862
Updated
2026-11-02
OSV 7.5

Apache ZooKeeper: Information disclosure via SetWatches reconnect replay

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.

Record
CVE-2026-59739
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness
CWE-862
Updated
2026-11-02
OSVDEBIAN-CVE-2026-59739 7.5

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.

Record
DEBIAN-CVE-2026-59739
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Updated
2026-11-02
OSVUBUNTU-CVE-2026-59739 7.5

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.

Record
UBUNTU-CVE-2026-59739
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Updated
2026-11-02
OSVBIT-zookeeper-2026-59739 No score

Apache ZooKeeper: Information disclosure via SetWatches reconnect replay

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.

Record
BIT-zookeeper-2026-59739
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
zookeeper
Bitnami
 3.8.0 up to 3.8.7, 3.9.0 up to 3.9.6
3.8.73.9.6
zookeeper
Debian:12
 All versions, plus listed versions
3.8.0-113.8.0-11+deb12u13.8.0-11+deb12u23.9.1-13.9.2-1
Show 8 moreShow less
3.9.2-23.9.3-13.9.3-23.9.4-13.9.4-23.9.5-13.9.5-23.9.6-1
 None known
zookeeper
Debian:13
 All versions, plus listed versions
3.9.3-13.9.3-1+deb13u13.9.3-23.9.4-13.9.4-23.9.5-13.9.5-23.9.6-1
 None known
zookeeper
Debian:14
 before 3.9.6-1, plus listed versions
3.9.3-13.9.3-23.9.4-13.9.4-23.9.5-13.9.5-2
3.9.6-1
zookeeper
Ubuntu:Pro:14.04:LTS
 All versions, plus listed versions
3.4.5+dfsg-13.4.5+dfsg-1ubuntu0.1~esm13.4.5+dfsg-1ubuntu0.1~esm3
 None known
zookeeper
Ubuntu:Pro:16.04:LTS
 All versions, plus listed versions
3.4.6-83.4.7-13.4.8-13.4.8-1ubuntu0.1~esm13.4.8-1ubuntu0.1~esm2
 None known
zookeeper
Ubuntu:Pro:18.04:LTS
 All versions, plus listed versions
3.4.10-23.4.10-33.4.13-33.4.13-3ubuntu0.1~esm1
 None known
zookeeper
Ubuntu:20.04:LTS
 All versions, plus listed versions
3.4.13-13.4.13-33.4.13-3build13.4.13-43.4.13-53.4.13-5build13.4.13-5ubuntu0.1
 None known
zookeeper
Ubuntu:22.04:LTS
 All versions, plus listed versions
3.4.13-5ubuntu43.4.13-6ubuntu23.4.13-6ubuntu33.4.13-6ubuntu43.4.13-6ubuntu4.1
 None known
zookeeper
Ubuntu:24.04:LTS
 All versions, plus listed versions
3.8.0-113.9.1-13.9.1-1build13.9.1-1build2
 None known
zookeeper
Ubuntu:26.10
 All versions, plus listed versions
3.9.5-13.9.5-2
 None known
zookeeper
Ubuntu:26.04:LTS
 All versions, plus listed versions
3.9.3-1build23.9.3-1build33.9.4-13.9.5-1
 None known

History

History
RecordedChangedSources
first indexedCVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-59739 is a high vulnerability (CVSS 7.5) in Apache Zookeeper, published September 16, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.55%, the 46th percentile. Fixed in zookeeper 3.8.7.

References

Pages All vulnerabilities Browse Docs Sources Guide Get API key
MoveEnter Open