CVE-2026-59969High· 7.5▾ TwilightApache 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 ena…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 41.3 · likelihood 0.1 · exploitation 0
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Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.
Exploit-prediction probability, daily snapshots since Sep 17.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.1%
— → 7.5
none → high
Last analysed / modified upstream
0.1% → 0.4%
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.
zookeeper >= 3.8.0, < 3.8.7zookeeper >= 3.9.0, < 3.9.6Upgrade past the affected range:
zookeeper 3.9.6Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-84439Medium· 5.3When audit logging is enabled (zookeeper.audit.enable=true), an unauthenticated attacker can inject arbitrary fields into Apache ZooKeeper's audit log by sending a digest authentication request with tab characters (\t) embedded in the us…
CVE-2026-79993High· 7.5The `deleteContainer` opcode (0x14/20) is processed without verifying the caller's ACL permissions, allowing any authenticated client to delete specific znodes in the data tree regardless of the ACL restrictions on the znode or its paren…
CVE-2026-59739High· 7.5Information disclosure via SetWatches reconnect replay in Apache ZooKeeper due to missing ACL check. An attacker can discover ACL-restricted paths by registering exists-watches on non-existent paths, then reconnecting after the paths are…
CVE-2026-84501Medium· 5.3An unauthenticated attacker can inject arbitrary fake log lines into Apache ZooKeeper's operational log by sending a crafted add_auth("ensemble", ...) request containing newline characters (\n)
CVE-2026-43869High· 7.3Improper Validation of Certificate with Host Mismatch vulnerability in Apache Thrift. This issue affects Apache Thrift: before 0.23.0. Users are recommended to upgrade to version 0.23.0, which fixes the issue.
CVE-2025-59060Medium· 5.3Hostname verification bypass issue in Apache Ranger NiFiRegistryClient is reported in Apache Ranger versions <= 2.7.0. Users are recommended to upgrade to version 2.8.0, which fixes this issue.