Known exploited · Trend Micro
CVE-2026-34926: Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability
What it is
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.
- Vendor
- Trend Micro
- Product
- Apex One
- Added to KEV
- May 21, 2026
- CISA due date
- June 4, 2026
- Ransomware use
- Unknown
- Weakness
- CWE-23: Relative Path Traversal
What CISA requires
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Forensic triage
No
What to do now
- Find every instance of Apex One you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before June 4, 2026 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
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Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.