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TI-2026-42763 Aliases CVE-2026-59969GHSA-4pv3-cr63-m4ph

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

Priority LOW 39CWE-297Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · High · None
Fix status
Partial Red Hat: 1 fixed, 5 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0033 26th percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ApacheApache ZooKeeper3.9.0 – 3.9.5; 3.8.0 – 3.8.6—No fix listedCNA
  • Apache ZooKeeper VendorApache Affected 3.9.0 – 3.9.5; 3.8.0 – 3.8.6 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:apache:zookeeper:*:*:*:*:*:*:*:*3.8.0 to before 3.8.7; 3.9.0 to before 3.9.6VulnerableApache
  • cpe:2.3:a:apache:zookeeper:*:*:*:*:*:*:*:* Versions 3.8.0 to before 3.8.7; 3.9.0 to before 3.9.6 Vulnerable ·Apache

Remediation

Red Hat 1 advisory

  • RHSA-2026:95221 Released 2026-11-04 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 8.1.9 XP 6.0.7.GA release
    • Red Hat JBoss Enterprise Application Platform 8.1

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat AMQ Broker 7AffectedNo fix yet
Red Hat JBoss Enterprise Application Platform Expansion PackAffectedNo fix yet
Red Hat Offline Knowledge PortalAffectedNo fix yet
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Red Hat build of Apache Camel for Spring Boot 4AffectedNo fix yet
Red Hat JBoss Enterprise Application Platform 8.1Fixed RHSA-2026:95221
Not affected: 6 products
  • Red Hat Fuse 7
  • Red Hat JBoss Enterprise Application Platform 8
  • Red Hat OpenShift AI (RHOAI)
  • Red Hat OpenStack Platform 13 (Queens)
  • Red Hat OpenStack Platform 16.2
  • Red Hat build of Apache Camel 4 for Quarkus 3

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-59969
  2. 2026-10-03 Alias added: GHSA-4pv3-cr63-m4ph
  3. 2026-10-06 Affected versions changed · Red Hat
  4. 2026-11-04 Fix available: RHSA-2026:95221 · Red Hat
  5. 2026-11-04 Fix available: Red Hat JBoss Enterprise Application Platform 8.1 · Red Hat

References

Advisory 2

  • TI-2017-03638 Missing authentication in Apache ZooKeeper CVSS 3.0HIGH 7.5
  • TI-2023-24043 Apache ZooKeeper: Authorization bypass in SASL Quorum Peer Authentication CVSS 3.1CRITICAL 9.1
  • TI-2021-04395 Possible request smuggling in HTTP/2 due missing validation CVSS 3.1MEDIUM 5.9
  • TI-2024-34425 Apache ZooKeeper: Authentication bypass with IP-based authentication in Admin Server CVSS 3.1CRITICAL 9.1
  • TI-2016-04336 Buffer overflow in the C cli shell in Apache Zookeeper before 3.4.9 and 3.5.x before… CVSS 3.0HIGH 8.1
  • TI-2018-05789 Missing authorization in Apache ZooKeeper CVSS 3.1HIGH 7.5
See all 15 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences