Apache ZooKeeper vulnerabilities: known CVEs & security history
Apache · Infra / Coordination · 11 tracked CVEs · 0 actively exploited · updated June 2026 · what is a CVE? →
This is the full list of known vulnerabilities (CVEs) across all Apache ZooKeeper release lines — 11 in total. A CVE here doesn't mean your version is affected — check Apache ZooKeeper's current status and the safe version to run.
Known Apache ZooKeeper CVEs
Actively-exploited and most-severe first. Open any CVE for full details.
| CVE | Severity | CVSS | EPSS | Year |
|---|---|---|---|---|
| CVE-2024-51504 | critical | 9.1 | 1% | 2024 |
| CVE-2023-44981 | critical | 9.1 | 2% | 2023 |
| CVE-2016-5017 | high | 8.1 | 8% | 2016 |
| CVE-2026-24308 | high | 7.5 | 1% | 2026 |
| CVE-2018-8012 | high | 7.5 | 9% | 2018 |
| CVE-2017-5637 | high | 7.5 | 74% | 2017 |
| CVE-2026-24281 | high | 7.4 | 0% | 2026 |
| CVE-2021-21295 | medium | 5.9 | 19% | 2021 |
| CVE-2019-0201 | medium | 5.9 | 10% | 2019 |
| CVE-2024-23944 | medium | 5.3 | 0% | 2024 |
| CVE-2025-58457 | medium | 4.3 | 0% | 2025 |
Is my Apache ZooKeeper version affected?
The list above spans every release. To know whether your version is affected — and the minimum safe version to upgrade to — check it directly.
Check your Apache ZooKeeper version → · Monitor Apache ZooKeeper for new CVEs →
Apache ZooKeeper vulnerabilities — frequently asked
How many known vulnerabilities does Apache ZooKeeper have?
IsItPatched tracks 11 CVEs for Apache ZooKeeper. 2 are critical-severity and 5 high-severity. These span every release line — what matters is whether the version you run is affected.
Does Apache ZooKeeper have any actively-exploited vulnerabilities?
None of Apache ZooKeeper's tracked CVEs are currently in CISA's KEV catalog — but new ones can be added at any time, so keep your version current.
What is the most severe Apache ZooKeeper vulnerability?
Among tracked issues, CVE-2024-51504 (CRITICAL, CVSS 9.1) ranks highest — a CWE-290 weakness.
Is Apache ZooKeeper safe to use?
It depends on the version. The latest supported Apache ZooKeeper release (3.9.5) clears the known issues; older versions may still be affected. Check the exact version you run for a verdict.
CVE data aggregated from NVD, CISA KEV and EPSS (FIRST.org). Related: Apache ZooKeeper security status · Apache ZooKeeper end-of-life · actively-exploited CVEs. Always verify against Apache's advisories — see our disclaimer.