Not rated
CVE-2026-59969 Apache ZooKeeper quorum TLS fails to enforce peer hostname verification in FIPS-mode deployments
Description
Apache ZooKeeper quorum TLS fails to enforce peer hostname verification in FIPS-mode deployments. When sslQuorum=true, zookeeper.fips-mode=true, ssl.quorum.hostnameVerification=true, and ssl.quorum.clientHostnameVerification=true are enabled, the Java SSLSocket quorum path accepts a CA-trusted peer certificate whose SAN does not match the connected host. A malicious or misissued peer certificate can therefore join quorum traffic, participate in leader election, and enter replication flows. Users are recommended to upgrade to version 3.8.7 or 3.9.6, which fixes the issue.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Apache ZooKeeper 3.9 | 3.9.0 → 3.9.5 | No fix stated |
| Apache ZooKeeper 3.8 | 3.8.0 → 3.8.6 | No fix stated |
References
- lists.apache.org lists.apache.org
Timeline
- Published
- Last modified
Other CVEs of Apache ZooKeeper
The 19 CVEs of Apache ZooKeeper →
CVE-2026-100302
Apache ZooKeeper: Denial of service through unbounded memory allocation in multiRead request handling
7.1
High
CVE-2026-115448
Apache ZooKeeper: Unbounded recursion in snapshot serialization allows a client to render the server unrecoverable
8.7
High
CVE-2026-100300
Apache ZooKeeper: Unauthenticated persistent denial of service via unvalidated quota-node data and paths crashing the transaction-apply thread
8.7
High
CVE-2026-100252
Apache ZooKeeper: SASL authorization bypass on the client port through a client-supplied authorization ID
8.6
High