CVE-2025-14963: trellix endpoint hx agent (xagent) Improper Input Validation

Vulnerability summary

CVE-2025-14963 is a high (CVSS 7.8) Improper Input Validation vulnerability in trellix endpoint hx agent (xagent). EPSS estimates a 0.11% chance of exploitation in the next 30 days, higher than 1% of scored vulnerabilities.

Timeline

1. 24-02-2026
   PublishedVulnerability first disclosed.
2. 26-02-2026
   Last modifiedVulnerability information updated.

Description

A vulnerability identified in the HX Agent driver file fekern.sys allowed a threat actor with local user access the ability to gain elevated system privileges. Utilization of a Bring Your Own Vulnerable Driver (BYOVD) was leveraged to gain access to the critical Windows process memory lsass.exe (Local Security Authority Subsystem Service). The fekern.sys is a driver file associated with the HX Agent (used in all existing HX Agent versions). The vulnerable driver installed in a product or a system running a fully functional HX Agent is, itself, not exploitable as the product’s tamper protection restricts the ability to communicate with the driver to only the Agent’s processes.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.