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TI-2026-55327 Aliases CVE-2026-79993GHSA-9x9g-5r48-3wvg

Missing authorization in Apache ZooKeeper

Priority MEDIUM 40CWE-862Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
Partial Red Hat: 1 fixed, 7 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-862.

Summary

The `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 parent. This opcode is considered internal-only and the official client doesn't have API for it, but a client that can open a plain TCP session on the ZooKeeper client port (2181 by default) - with NO authentication and NO ACL permissions - can delete any empty persistent znode (including regular persistent nodes, container nodes, and TTL nodes) by issuing the raw protocol OpCode deleteContainer (20). The deleteContainer request path completely skips both the session check and the DELETE ACL check that are enforced by the regular delete (OpCode 2) path. This is an authorization bypass / ACL enforcement bug. This issue affects Apache ZooKeeper: from 3.9.0 through 3.9.5, from 3.8.0 through 3.8.6. Users are recommended to upgrade to version 3.9.6 or 3.8.7, which fixes the issue.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00603 49th percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 7 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-2026:83612 Released 2026-10-15 · Red Hat rating Important
    Red Hat build of Debezium 3.6.3 release
    • Red Hat Build of Debezium 3.6

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat AMQ Broker 7AffectedNo fix yet
Red Hat Data Grid 8AffectedNo fix planned: Will not fix
Red Hat Fuse 7AffectedNo fix planned: Will not fix
Red Hat JBoss Enterprise Application Platform 7AffectedNo fix planned: Will not fix
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Red Hat build of Apache Camel for Spring Boot 4AffectedNo fix yet
Red Hat build of Debezium 3AffectedNo fix yet
Red Hat Build of Debezium 3.6Fixed RHSA-2026:83612
Not affected: 6 products
  • Red Hat JBoss Enterprise Application Platform 8
  • Red Hat JBoss Enterprise Application Platform Expansion Pack
  • Red Hat Offline Knowledge Portal
  • Red Hat OpenShift AI (RHOAI)
  • streams for Apache Kafka 2
  • streams for Apache Kafka 3

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-79993
  2. 2026-10-03 Alias added: GHSA-9x9g-5r48-3wvg
  3. 2026-10-09 Affected versions changed · Red Hat
  4. 2026-10-09 CVSS score added · Red Hat
  5. 2026-10-13 Affected versions changed · Red Hat
  6. 2026-10-16 Fix available: RHSA-2026:83612 · Red Hat
  7. 2026-10-16 Fix available: Red Hat Build of Debezium 3.6 · Red Hat
  8. 2026-10-30 Affected versions changed · Red Hat
  9. 2026-11-03 Affected versions changed · Red Hat

References

Advisory 1

  • 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