Every exploited vulnerability / Oracle
CVE-2023-21839 in Oracle WebLogic Server: known exploited
Generated from its entry in CISA's catalogue of known exploited vulnerabilities as of 3 November 2026.
Attackers are exploiting CVE-2023-21839 in Oracle WebLogic Server. CISA has listed it as known exploited since 1 May 2023.
| Product | Oracle WebLogic Server |
|---|---|
| Known exploited since | 1 May 2023 |
| Ransomware use | Not recorded |
| EU vulnerability database | EUVD-2023-26005 |
| Sources | NVD · CISA KEV |
What it means
Attackers have used this vulnerability in real attacks. An unpatched Oracle WebLogic Server that can be reached from the internet is exposed to them.
What to do
- Apply the vendor's fix to every system running Oracle WebLogic Server, starting with those reachable from the internet. Take a system off the internet until it can be fixed.
- Check the system for signs that it was reached before the fix.
How Vardion finds it
Wherever a scan or your imported scanner results find CVE-2023-21839, Vardion names the systems affected and puts the fix at the top of the list.