🔐 CVE Alert

CVE-2026-59969

UNKNOWN 0.0

Apache ZooKeeper: Improper validation of certificate with host mismatch in FIPS mode

CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-297
Vendor apache software foundation
Product apache zookeeper
Published Sep 16, 2026
Last Updated Sep 16, 2026
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Affected Versions

Apache Software Foundation / Apache ZooKeeper
3.9.0 ≤ 3.9.5 3.8.0 ≤ 3.8.6

References

NVD ↗ CVE.org ↗ EPSS Data ↗
lists.apache.org: https://lists.apache.org/thread/qf9kwsgtgbgtvwls6f41281846xg0rss openwall.com: http://www.openwall.com/lists/oss-security/2026/09/15/4

Credits

🔍 Erichen <[email protected]>