Known exploited vulnerability · CISA KEV

CVE-2026-34926: Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability

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.

CVE-2026-34926

Exploited in the wild. Fix this first.

CISA added it to the Known Exploited Vulnerabilities catalog on 2026-05-21: attackers are using it right now.

CISA KEV: Listed; Added 2026-05-21 · federal fix-by 2026-06-04
EPSS (30 days): 13%; Higher than 96% of CVEs · 2026-11-01
CVSS v3.1: 6.7 Medium; CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L

What CISA says

Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

NVD description · published 2026-05-21

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.

Full record on NVD

Got a whole scan? Scan Hub runs this check on every finding in your Nessus, Qualys, Rapid7 or OpenVAS export and ranks the report by it.

Try it free

How to check if you are exposed to CVE-2026-34926

Find every Trend Micro Apex One system you or your clients run, including ones exposed to the internet. Those come first: CISA only lists flaws attackers are already using.
Compare each version with the fixed versions in the vendor advisory below. Where no fix exists yet, apply the vendor’s mitigation or take the system off the internet.
Run a credentialed vulnerability scan to catch the systems you missed, then check that the next scan no longer reports CVE-2026-34926.

US federal agencies had to fix this by 2026-06-04. Everyone else should treat that deadline as a guide: if it has passed, this is overdue.

Affected versions

Versions the National Vulnerability Database lists as vulnerable to CVE-2026-34926. Check the vendor advisory for the exact fixed builds before you sign anything off.

Product	Vulnerable versions
Trend Micro Apex ONE	before 14.0.0.17079; before 14.0.20731

Timeline

2026-05-21 · Published in the National Vulnerability Database
2026-05-21 · Added to CISA's Known Exploited Vulnerabilities catalog, the same day it was published
2026-06-04 · Fix-by date for US federal agencies, passed 150 days ago

Vendor advisories and fixes

https://success.trendmicro.com/en-US/solution/KA-0023430

Weakness type

CWE-23

More exploited Trend Micro vulnerabilities

CISA lists 12 exploited Trend Micro vulnerabilities. The closest matches:

Keep going

Sources: CISA Known Exploited Vulnerabilities catalog (version 2026.10.30); EPSS data from FIRST.org; CVSS and descriptions from the NIST National Vulnerability Database. Checked 2026-11-01. This product uses the NVD API but is not endorsed or certified by the NVD.