Trend Micro · Apex One · Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability
Verdict
Patch on your normal cycle · actively exploited, not reachable unauthenticated from the internet, and in the upper half of CVEs by near-term exploitation probability
Added to CISA KEV 2026-05-21 · exploited in the wild for 129 days
CVSS 6.7 MEDIUM. The score is a summary; these three components are the part that decides whether something scanning the internet can use it.
| Attack vector | localrequires local access to the machine |
|---|---|
| Privileges required | highneeds elevated privileges before it can be used |
| User interaction | nonecan be triggered with nobody interacting with the page or request |
| Base vector | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L |
| Weakness | CWE-23 |
This describes the vulnerability. It says nothing about whether your systems run it.
EPSS puts the probability of exploitation in the next 30 days at 0.0054, which places it in the upper half of all tracked CVEs. The percentile is the more useful half: 0.18 in absolute terms sounds low until you know most of the internet-facing software in the world scores under that.
| EPSS probability | 0.0054 |
|---|---|
| Percentile | 0.430 — upper half |
| Added to KEV | 2026-05-21 |
|---|---|
| Days exploited | 129 |
| Federal remediation due | not set |
| Ransomware use | no known ransomware campaign use |
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
A directory traversal vulnerability in the Apex One (on-premise) server could allow a pre-authenticated local attacker to modify a key table on the server to inject malicious code to deploy to agents on affected installations. This vulnerability is only exploitable on the on-premise version of Apex One and a potential attacker must have access to the Apex One Server and already obtained administrative credentials to the server via some other method to exploit this vulnerability.