CVE-2026-59786

Active agent heartbeat missing TLS check

Published Oct 5, 2026 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed
Description
Zabbix Server and Proxy accept the active agent heartbeat message regardless of the configured PSK or certificate authentication. This means someone with access to the Zabbix trapper port can report an arbitrary host using an active agent as available, resulting in a loss of integrity.

Remediation

Vendor Solution

Update the affected components to their respective fixed versions.

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
Weaknesses CWE-306
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}

threat_severity

Moderate

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, '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 Zabbix Server and Proxy accept the active agent heartbeat message regardless of the configured PSK or certificate authentication. This means someone with access to the Zabbix trapper port can report an arbitrary host using an active agent as available, resulting in a loss of integrity.
Title Active agent heartbeat missing TLS check
Weaknesses CWE-940
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Zabbix
Published
Updated
Oct 5, 2026, 11:25 AM
Reserved
Jul 7, 2026, 8:30 AM
Status
Awaiting Analysis
Published
Oct 5, 2026, 11:16 AM
Modified
Oct 6, 2026, 3:27 PM
Severity
Moderate
Public date
Oct 5, 2026, 10:29 AM