CVE-2023-21839: Oracle WebLogic Server Unspecified Vulnerability

Is it exploited?

Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 1 May 2023, 104 days after the CVE record was published.

How likely is exploitation in the next 30 days?

99.9%

EPSS score, percentile 100 of all scored records

How severe?

7.5 High

CVSS v3.1 base score, given by the CNA

What should I do?

Required action (CISA), due 22 May 2023: Apply updates per vendor instructions.

Advisories and patches (1)

Which versions are affected?

Affected: 12.2.1.3.0; 12.2.1.4.0; 14.1.1.0.0

Versions by product

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

What to do

CISA due date for this action: 22 May 2023.

Advisories and patches

• Oracle Advisory (Vendor advisory)

Linked from CISA's catalog entry

• https://www.oracle.com/security-alerts/cpujan2023.html
• https://nvd.nist.gov/vuln/detail/CVE-2023-21839

Affected products and versions

As listed in the CVE record.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

About this vulnerability

Oracle WebLogic Server contains an unspecified vulnerability that allows an unauthenticated attacker with network access via T3, IIOP, to compromise Oracle WebLogic Server.

Summary: CISA's KEV catalog, as of 28 Oct 2026.

• CISA added CVE-2023-21839 to its Known Exploited Vulnerabilities (KEV) catalog on 1 May 2023.
• CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
• The due date CISA sets for the required action is 22 May 2023.
• The CVE record was published on 17 Jan 2023, 104 days before it was added to KEV.
• The CVE record carries a CVSS v3.1 base score of 7.5 (High), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 99.9% (percentile 100), as of 28 Oct 2026.
• CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact partial.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.

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).

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

Weakness

• CWE-306: Missing Authentication for Critical Function

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.

Timeline

References

• packetstormsecurity.com

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