CVE-2026-59781

Improper validation of custom installation directories on Windows could allow installation into locations with unsafe permissions, increasing the risk of DLL sideloading.

Published Aug 18, 2026 CVSS 4.0 · 5.4 Medium EPSS < 1% KEV · Not listed
Description
When Zabbix Agent was installed on Windows into a custom installation directory, the installer did not verify whether the selected directory had secure access permissions. If the target directory allowed unauthorized users to modify its contents, an attacker could place a malicious DLL that could later be loaded by the application, resulting in DLL sideloading. The installer has been hardened to detect potentially unsafe installation directories and now requires explicit user confirmation before proceeding with installation in such locations. This reduces the risk of accidental installation into directories with inappropriate permissions while preserving compatibility with existing deployment scenarios.

Remediation

Vendor Solution

Update the affected components to their respective fixed versions.


Vendor Workaround

Install the Zabbix Agent into directories with appropriately restricted access permissions. Verify and adjust permissions on custom installation directories to prevent unprivileged users from modifying their contents.

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:zabbix:zabbix:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Zabbix
Zabbix zabbix
Vendors & Products Zabbix
Zabbix zabbix
Type Values Removed Values Added
Description When Zabbix Agent was installed on Windows into a custom installation directory, the installer did not verify whether the selected directory had secure access permissions. If the target directory allowed unauthorized users to modify its contents, an attacker could place a malicious DLL that could later be loaded by the application, resulting in DLL sideloading. The installer has been hardened to detect potentially unsafe installation directories and now requires explicit user confirmation before proceeding with installation in such locations. This reduces the risk of accidental installation into directories with inappropriate permissions while preserving compatibility with existing deployment scenarios.
Title Improper validation of custom installation directories on Windows could allow installation into locations with unsafe permissions, increasing the risk of DLL sideloading.
Weaknesses CWE-427
References
Metrics cvssV4_0

{'score': 5.4, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Zabbix
Published
Updated
Aug 19, 2026, 3:55 AM
Reserved
Jul 7, 2026, 8:30 AM
Status
Analyzed
Published
Aug 18, 2026, 1:17 PM
Modified
Sep 23, 2026, 3:42 PM