How severe is CVE-2023-21839?

CVE-2023-21839 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-21839?

Affected package information for CVE-2023-21839 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2023-21839?

No fixed version has been published for CVE-2023-21839 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2023-21839 actively exploited in the wild?

Yes. There are 16 known exploit references for CVE-2023-21839, including 10 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2023-21839?

CVE-2023-21839 has an EPSS (Exploit Prediction Scoring System) score of 94.2%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2023-21839 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2023-21839 (Oracle WebLogic Server Unspecified Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2023-05-01. CISA required all US federal civilian agencies to remediate this vulnerability by 2023-05-22. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2023-21839?

CVE-2023-21839 is classified as Deserialization of Untrusted Data (CWE-502), Missing Authentication (CWE-306). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Which products and versions are affected by CVE-2023-21839?

CVE-2023-21839 affects oracle weblogic server (3 versions, e.g. 12.2.1.3.0, 12.2.1.4.0, 14.1.1.0.0). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2023-21839 published, and has it been updated?

CVE-2023-21839 was published on January 18, 2023 and was last updated on October 27, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2023-05-01 — agencies required to remediate by 2023-05-22

CVE-2023-21839

HIGH

Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: Core). Supported versions that are affected are 12.2.1.3.0, 12.2.1.4.0 and 14.1.1.0.0.…

Published

Jan 18, 2023

Updated

Oct 27, 2025

Affected

0 pkgs

Patched

None yet

Exploits

16 known

EPSS Exploitation Probability

via FIRST.org ↗

94.2%probability of exploitation in next 30 days

Very High Risk100th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: Core). Supported versions that are affected are 12.2.1.3.0, 12.2.1.4.0 and 14.1.1.0.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via T3, IIOP to compromise Oracle WebLogic Server. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Oracle WebLogic Server accessible data. CVSS 3.1 Base Score 7.5 (Confidentiality impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).

Affected Products

1 product · 3 configurations

Application

weblogic serveroracle

3 versions

12.2.1.3.012.2.1.4.014.1.1.0.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.