Advisory severityHigh7.5Apache Software Foundation

High [CVE-2024-23944 +1] Information disclosure via SetWatches reconnect replay in Apache ZooKeeper due to missing ACL check

This high-severity Apache Software Foundation advisory covers CVE-2026-59739 and CVE-2024-23944; related products: Apache ZooKeeper.

Aggregated and source-linked by VulniPulse. Data sources, validation and limitations. This bulletin covers 2 CVEs; its score, affected versions and guidance may apply to different issues within that bulletin.

CVE-2026-59739 Source published Sep 16, 2026Source updated Sep 18, 2026

VulniPulse record published Sep 16, 2026Record updated Sep 18, 2026

CVE-2024-23944 CVE-2026-59739

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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 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.

Affected versions

Apache ZooKeeper 3.9.0 through 3.9.5
Apache ZooKeeper 3.8.0 through 3.8.6

Official advisory · high-confidence parse· fetched 20 days ago·verify at source

Fixed versions

3.9.6
3.8.7

Official advisory · high-confidence parse· fetched 20 days ago·verify at source

Mitigation checklist

Recommended fix / mitigation

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

Official advisory · high-confidence parse· fetched 20 days ago·verify at source

Sources

Official and corroborating records used to build this advisory.

Official vendor advisoryofficial
Official advisory page fetched and parsed; accepted detail fields are attributed to this page.
Apache Software Foundation
CVE.org CNA recordCVE.org
Independent CNA record used for near-real-time discovery and missed-CVE reconciliation. Discovered from the machine-readable feed https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/delta.json; this link opens the CVE.org record for CVE-2024-23944 instead of the raw feed document.
CVE Program

Cross-references

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Official resources

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Official documentation
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Apache project downloads (fixed releases)
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