// What runs on ZooKeeper / accumulo
Does Apache Accumulo use ZooKeeper?
RequiredYes. Accumulo requires HDFS and ZooKeeper to be configured and running, in every release line. Even the Accumulo 4.0 alpha keeps system fault-tolerant executor (FaTE) transactions in ZooKeeper.
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What Apache Accumulo uses ZooKeeper for
- Instance and table configuration, and tablet server locks.
- Fault-tolerant executor (FaTE) transaction state.
Which ZooKeeper version ships with Apache Accumulo
From the zookeeper.version property in pom.xml at each release tag.
| Release | ZooKeeper | ZooKeeper line status | Open ZooKeeper CVEs |
|---|---|---|---|
| Accumulo 1.10.4 | 3.4.14 | End of life since 1 June 2020Bundles log4j 1.2.17 | 1 (CVE-2023-44981)2026 advisories not assessed for this line |
| Accumulo 2.1.6 | 3.9.5 | Supported (latest 3.9.6) | 3 (CVE-2026-59739, CVE-2026-59969, CVE-2026-79993) |
| Accumulo 3.0.0 | 3.8.2 | Supported (latest 3.8.7) | 7 (CVE-2023-44981, CVE-2024-23944, CVE-2026-24281, CVE-2026-24308, CVE-2026-59739, CVE-2026-59969, CVE-2026-79993) |
CVE counts are ZooKeeper's own advisories matched against the upstream version. The Apache ZooKeeper project does not assess end-of-life lines against new advisories, so "not assessed" means unknown, not safe.
What ZooKeeper 3.4.14 is exposed to
CVE-2023-44981 · CVSS 9.1 · fixed in 3.7.2, 3.8.3, 3.9.1
SASL quorum peer authentication bypass, giving full read-write access to the data tree. Applies when quorum.auth.enableSasl=true.
Find the ZooKeeper Accumulo is using
grep -E '^instance.zookeeper.host' conf/accumulo.properties ls lib/ | grep -E '^zookeeper-[0-9]'
Can Apache Accumulo run without ZooKeeper?
No.
Accumulo 2.1.6 (July 2026) and 3.0.0 are the released lines; 4.0 is in alpha.
Your options
Upgrade Accumulo
Accumulo 1.10 builds against ZooKeeper 3.4.14. Moving to 2.1 brings a supported ZooKeeper client.
Patch the ensemble
OSSeva patches the ZooKeeper ensemble under Accumulo and the Hadoop layer beside it.
Most teams buy this at the product level: keep the Apache Accumulo estate supported, including the ZooKeeper under it. See Accumulo extended support.
Frequently asked questions
Can Accumulo run without ZooKeeper?
No. Every Accumulo release requires ZooKeeper and HDFS.
Keep Apache Accumulo and the ZooKeeper under it supported.
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