CVE-2020-8599: in the CISA KEV catalogue
Trend Micro Apex One and OfficeScan Authentication Bypass Vulnerability. CISA added CVE-2020-8599 to the Known Exploited Vulnerabilities catalogue on 2021-11-03 with a default due date of 2022-05-03. Known ransomware campaign use: Unknown. Forensic triage flag: No.
Trend Micro Apex One and OfficeScan server contain a vulnerable EXE file that could allow a remote attacker to write data to a path on affected installations and bypass root login. (CISA description)
- Vendor / product
- Trend Micro Apex One and OfficeScan
- CWE
- Not listed
- CISA required action
- Apply updates per vendor instructions.
- EPSS
- 12%, percentile 96 (scored 2026-11-03)
EPSS puts about 12 in 100 odds (12%) on exploitation activity being observed in the next 30 days. Its score is higher than or equal to that of 96% of scored CVEs. This is a model estimate about exploitation anywhere, not about your environment.
Vendor and reference links (from CISA)
Your own deadline under CISA BOD 26-04 depends on exposure, automatability and technical impact: work it out with the BOD 26-04 calculator.
Frequently asked questions
Is CVE-2020-8599 in the CISA KEV catalogue?
Yes. CISA added CVE-2020-8599 (Trend Micro Apex One and OfficeScan Authentication Bypass Vulnerability) to the Known Exploited Vulnerabilities catalogue on 2021-11-03. CISA's default due date for it is 2022-05-03.
Is CVE-2020-8599 used in ransomware attacks?
CISA marks known ransomware campaign use as Unknown for CVE-2020-8599. That means CISA lacks confirmation, not that ransomware groups do not use it.
What should I do about CVE-2020-8599?
CISA's required action: Apply updates per vendor instructions.
Sources
- CISA, Known Exploited Vulnerabilities Catalog (accessed 2026-11-03)
- FIRST, Exploit Prediction Scoring System (EPSS) (EPSS by FIRST; scores generated by Empirical Security)
- NVD record for CVE-2020-8599