CVE-2025-14963: Trellix Endpoint HX Agent (xAgent) · Improper Input Validation
Affects Trellix Endpoint HX Agent (xAgent)Source CVE Database V5
Public exploit available · CVSS 6.2 Medium.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:PExploitation evidence
Disclosed: evidence found.
CVE published 24 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| TrellixEndpoint HX Agent (xAgent) | Affected
| Fixed in– |
AI-suggested
Organizations should immediately verify that their Trellix Endpoint HX Agent installations are updated to versions beyond those affected (post 36.30.0-17 or vendor-released patches once available). In the interim, enforcing the principle of least privilege to limit local user elevated access reduces exploitation risk. Strengthening endpoint security policies to prevent unauthorized driver loading and monitoring for unusual driver activity can help detect BYOVD attempts. Employing application control or driver signing enforcement mechanisms can block unauthorized or vulnerable drivers from loading. Additionally, monitoring access to lsass.exe memory and implementing credential protection technologies (such as Windows Credential Guard) can mitigate credential theft risks. Regularly auditing and restricting local administrative privileges, combined with tamper protection verification, will further reduce the attack surface. Incident response teams should be prepared to investigate any suspicious local privilege escalation attempts related to driver manipulation.
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.