7.5

CVE-2026-79993: apache software foundation apache zookeeper Missing Authorization

CVSS: 7.5v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-79993DEBIAN-CVE-2026-79993
Published 16-09-2026Last modified 17-09-2026
Open JSON

Vulnerability summary

CVE-2026-79993 is a high (CVSS 7.5) Missing Authorization vulnerability in apache software foundation apache zookeeper. EPSS estimates a 0.60% chance of exploitation in the next 30 days, higher than 47.7% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.60%
0%100%
Low · +0.10 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 16-09-2026
    PublishedVulnerability first disclosed.
  2. 17-09-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.60%

Chance of exploitation in the next 30 days

Percentile

48%

Versus all other CVEs

30-day change

+0.10 pp

From 0.50% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.60%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Apache1 product
  • zookeeper≥ 3.8.0, < 3.8.7 | ≥ 3.9.0, < 3.9.6
Apache software foundation1 product
Debian1 product
  • zookeeperAll versions (No fix recorded) | < 3.9.6-1
Ubuntu1 product
  • zookeeperAll versions (No fix recorded)

4 vendors · 4 products

References

5 links