# CVE-2026-79993: zookeeper: The `deleteContainer` opcode (0x14/20) is processed without verifying the caller's ACL permissions, allowing any auth...

CVE-2026-79993 is fixed in zookeeper on 1 platform by DEBIAN-CVE-2026-79993 (version 3.9.6-1), released September 26, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-79993
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0060
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 16, 2026

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | zookeeper Debian 14 | 3.9.6-1 | [DEBIAN-CVE-2026-79993](https://patchblox.com/security/data/fix/linux/debian-cve-2026-79993.md) | Sep 26, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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