Exploited. On CISA's list since 2026-05-21.
Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability
CVE-2026-34926 · Trend Micro Apex One · Published 2026-05-21
How bad would it be?
6.7 out of 10
CVSS rates it medium.
How likely is it to be used?
13%
Estimated chance of exploitation in the next 30 days, higher than 96% of all scored flaws (EPSS, 2026-10-29).
Is it already being used?
Yes
CISA has seen it exploited in real attacks. For US government agencies the fix is deadline passed 148 days ago (2026-06-04).
What CISA says to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Trend Micro Apex One (on-premise) contains a directory traversal vulnerability that 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.
What the flaw is
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.
From the NVD.
Fixes and advisories
Learn this
Explore this week’s weaknesses and all learning topics
Understand the kind of weakness behind this flaw. These resources teach the weakness, rather than reproduce this specific CVE. Follow the vendor's advice above to fix the affected product.
CWE-23 · CISA KEV; NVD record: security@trendmicro.com. We have not selected a close learning match for this label.
CWE is a catalogue of weakness types. Labels come from the sources shown and can differ or change. Resource matches reviewed 16 October 2026.
On SentryFeed
No story in the last 14 days has mentioned it.
Exploited flaws from CISA's KEV catalogue. Chance of exploitation from EPSS by FIRST. Descriptions and scores from the NVD. This product uses the NVD API but is not endorsed or certified by the NVD.