---
title: "CVE-2026-34926: Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability"
url: https://erroneo.us/security/cve/CVE-2026-34926/
description: "CVE-2026-34926 (Trend Micro Apex One): Exploited in the wild (CISA KEV). A directory traversal vulnerability in the Apex One (on-premise) server could allow…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-05-21
date_modified: 2026-05-22
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-34926"
kev: true
cvss: 6.7
epss: 0.00538
license: All rights reserved. Quote with attribution and a link.
---

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

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Trend Micro Apex One. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-05-21, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-06-04 ; treat that as the outer limit, not the target.
- EPSS 0.5% , percentile 44: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 44% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs local access needed. Lower urgency for most teams unless an attacker could already run code on the machine.

## What it 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.

## Affected products (CVE record)

- Trend Micro, Inc. TrendAI Apex One: 2019 (14.0) < 14.0.0.17079
- Trend Micro, Inc. TrendAI Apex One as a Service: SaaS < 14.0.20731

## Severity

- trendmicro CVSS 3.1: 6.7 `CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L`

## Exploitation

- CISA KEV: added 2026-05-21; federal due date 2026-06-04. Known ransomware use: Unknown.
- CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.54% probability of exploitation activity in the next 30 days; percentile 44.

## Sources

- [Listed in CISA KEV notes (success.trendmicro.com)](https://success.trendmicro.com/en-US/solution/KA-0023430)
- [CVE.org record CVE-2026-34926](https://www.cve.org/CVERecord?id=CVE-2026-34926)
- [NVD entry CVE-2026-34926](https://nvd.nist.gov/vuln/detail/CVE-2026-34926)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-34926)
- [success.trendmicro.com](https://success.trendmicro.com/ja-JP/solution/KA-0022974)
- [jvn.jp](https://jvn.jp/en/vu/JVNVU90583059/)
- [jpcert.or.jp](https://www.jpcert.or.jp/english/at/2026/at260014.html)

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Source page: https://erroneo.us/security/cve/CVE-2026-34926/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt