CVE-2026-79993
Apache ZooKeeper: Missing ACL check on deleteContainer opcode allows unauthorized deletion of any empty persistent/container znode
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.
INFO
Published Date :
Sept. 16, 2026, 10:16 a.m.
Last Modified :
Sept. 18, 2026, 2:37 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Upgrade ZooKeeper to version 3.9.6 or 3.8.7.
- Apply vendor-provided patches if upgrading is not possible.
- Ensure proper ACL enforcement for ZooKeeper operations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-79993.
| URL | Resource |
|---|---|
| https://lists.apache.org/thread/9cw3rmrzhqpct26v8j18fy41bghlq8y5 | Mailing List Vendor Advisory |
| http://www.openwall.com/lists/oss-security/2026/09/15/5 | Mailing List |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-79993 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-79993
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-79993 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-79993 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Sep. 18, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:apache:zookeeper:*:*:*:*:*:*:*:* versions from (including) 3.8.0 up to (excluding) 3.8.7 *cpe:2.3:a:apache:zookeeper:*:*:*:*:*:*:*:* versions from (including) 3.9.0 up to (excluding) 3.9.6 Added Reference Type Apache Software Foundation: https://lists.apache.org/thread/9cw3rmrzhqpct26v8j18fy41bghlq8y5 Types: Mailing List, Vendor Advisory Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/09/15/5 Types: Mailing List -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 17, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Added SSVC {'id': 'CVE-2026-79993', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-17T19:15:43.099911Z'} -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Sep. 16, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/09/15/5 -
New CVE Received by [email protected]
Sep. 16, 2026
Action Type Old Value New Value Added 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. Added CWE CWE-862 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/79xxx/CVE-2026-79993.json">CVE-2026-79993</a> Added Reference https://lists.apache.org/thread/9cw3rmrzhqpct26v8j18fy41bghlq8y5