Trend Micro Apex One
CVE-2026-34926
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 this means for your business
- It affects Trend Micro Apex One. It matters if your company, or a supplier that handles your data, runs it.
- Attackers are already using it. CISA added it to its list of flaws used in real attacks on 21 May 2026.
- FIRST's prediction model gives it a 13% chance of attack attempts being seen in the next 30 days, ranking above 96% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Trend Micro Apex One.
- 2If you do, follow CISA's required action below. No patch reference has been published yet.
- 3Treat it as urgent. US federal agencies must fix it by 4 June 2026. That deadline does not apply to private companies, but it shows how seriously CISA takes it.
- 4Because attackers have used it, check the affected systems for signs of a break-in, not only for the update.
Fastnexa security experts
Attackers are already using this flaw. Is your Trend Micro Apex One exposed?
Tell us where you run Trend Micro Apex One and a Fastnexa penetration tester will check whether this flaw, or others like it, can be used against your websites, apps and network.
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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’s wording, unedited.
Scoring
- CVSS
- Not yet scored
Dates
- Published
- 2026-05-21
- Added to KEV
- 2026-05-21
- Remediation due
- 2026-06-04
- Sources
- CISA KEV