---
title: "CVE-2026-59739: Apache ZooKeeper - Information Disclosure"
description: "Apache ZooKeeper contains an information disclosure vulnerability caused by missing ACL check in SetWatches reconnect replay, letting attackers discover ACL-restricted paths by registering exists-watches on non-existent paths and reconnecting after path creation, exploit requires ability to register watches and reconnect."
url: https://panop.io/threat-heartbeat/CVE-2026-59739/
---

# CVE-2026-59739 Apache ZooKeeper - Information Disclosure

Apache ZooKeeper contains an information disclosure vulnerability caused by missing ACL check in SetWatches reconnect replay, letting attackers discover ACL-restricted paths by registering exists-watches on non-existent paths and reconnecting after path creation, exploit requires ability to register watches and reconnect.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

None known

EPSS

0.55% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-59739)

## Details

Type

Information Disclosure

Impact

Information Disclosure

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Published

16 September 2026

Updated

15 October 2026

Weakness

[CWE-862](https://cwe.mitre.org/data/definitions/862.html)

## Vendor fix

Upgrade to version 3.9.6 or 3.8.7.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-59739](https://nvd.nist.gov/vuln/detail/CVE-2026-59739)
- [https://lists.apache.org/thread/v0lrwsbdxvx6w67p3z7fxf3hzyncq55l](https://lists.apache.org/thread/v0lrwsbdxvx6w67p3z7fxf3hzyncq55l)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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