CVE-2025-36546: F5OS Appliance Mode vulnerability

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-05-07 · updated 2026-06-17
Weakness: CWE-863

Description

On an F5OS system, if the root user had previously configured the system to allow login via SSH key-based authentication, and then enabled Appliance Mode; access via SSH key-based authentication is still allowed. For an attacker to exploit this vulnerability they must obtain the root user's SSH private key. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Affected products

F5OS - Appliance: from 1.5.1 before 1.5.3 — fixed in 1.5.3
F5OS - Chassis: from 1.6.0 through 1.6.2

How to fix

Upgrade to a fixed version: F5OS - Appliance 1.5.3. Check the vendor advisory for mitigations.

References

https://my.f5.com/manage/s/article/K000140574

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