CVE-2026-34926
Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability
Trend Micro Apex One
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.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 21 May 2026. US federal agencies were required to remediate it by 4 June 2026.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 13.4%, which is higher than 96.4% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L
Frequently asked questions
Is CVE-2026-34926 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2026-34926.
What does CVE-2026-34926 affect?
CVE-2026-34926 affects Trend Micro Apex One. 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.
How severe is CVE-2026-34926?
CVE-2026-34926 is rated MEDIUM with a CVSS base score of 6.7. EPSS puts the probability of exploitation in the next 30 days at 13.4%, higher than 96.4% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 4 June 2026.
How should organisations respond to CVE-2026-34926?
Apply the vendor patch for Trend Micro Apex One as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.