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Oracle WebLogic Server EUVDEUVD-2026-106577

| CVE-2026-91323 CRITICAL
Improper Authentication (CWE-287)
2026-10-20 secalert_us@oracle.com GHSA-x85m-p8wc-pg7r
9.8
CVSS 3.1 · Vendor: oracle
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Identify exposed WebLogic HTTP listener
  2. Delivery
    Send crafted HTTP request to Core
  3. Exploit
    Trigger server-side flaw
  4. Execution
    Execute attacker-controlled logic
  5. Impact
    Full WebLogic Server takeover

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Authentication mechanism validation
MITRE ATT&CK

2 techniques across 2 tactics: Defense Evasion, Initial Access

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

No special conditions - remote unauthenticated exploitation over HTTP against default configurations of Oracle WebLogic Server (Core component), per the Oracle description stating an unauthenticated attacker with network access via HTTP can take over the server (CVSS PR:N/UI:N/AC:L). The practical limiting factors are therefore network reachability of the WebLogic HTTP/T3 listener (exposure can be reduced by firewalling or restricting the admin/managed-server ports) and running one of the affected versions 12.2.1.4.0, 14.1.1.0.0, 14.1.2.0.0, or 15.1.1.0.0; no authentication, user interaction, or non-default feature toggle is required. The exact vulnerable Core feature is not specified because the CWE is 'N/A' in the source data.

Impact

All available signals point to a genuine top-priority vulnerability. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, base 9.8) describes an unauthenticated, network-reachable flaw with low attack complexity, no user interaction, and full confidentiality/integrity/availability impact resulting in complete server takeover - the highest-risk profile a single component flaw can have. These CVSS signals are internally consistent with the Oracle description, which explicitly states 'unauthenticated attacker with network access via HTTP' and 'takeover of Oracle WebLogic Server.' However, several real-world-risk signals are MISSING from the input and must be stated explicitly: no EPSS exploitation-probability score is provided, CISA KEV status is not indicated (treated as NO), no public POC is referenced, no SSVC decision data is supplied, and the CWE is 'N/A' so the exact flaw class (deserialization, SSRF, auth bypass, etc.) cannot be confirmed. Historically Oracle WebLogic unauthenticated RCE/takeover flaws in the Core component are rapidly weaponized and heavily targeted (e.g. prior deserialization CVEs appeared in KEV), so despite the current absence of KEV/POC/EPSS data this should be treated as an imminent patch priority rather than a 'high-CVSS-but-low-real-risk' issue. The one data inconsistency to flag: the input Tag 'Information Disclosure' conflicts with the C:H/I:H/A:H 'takeover' impact, which is far broader than mere disclosure - verify against the Oracle CPU advisory.

Exploit ScenarioDerived

A remote attacker with no credentials sends a crafted HTTP request directly to an internet- or network-exposed WebLogic Server Core listener, exploiting the flaw to achieve full compromise of the server. Because the attack requires no authentication, no user interaction, and only low complexity, a single request against a default-configured instance can lead to complete takeover. No public exploit identified at time of analysis, but the profile matches historically mass-scanned WebLogic flaws.

Act Now Prioritize within 24-48h. Why: CRITICAL severity.
No patch listed yet 0.5% exploitation probability (EPSS)

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AnalysisAIv1 – Oct 20, 2026

Unauthenticated remote takeover of Oracle WebLogic Server 12.2.1.4.0, 14.1.1.0.0, 14.1.2.0.0, and 15.1.1.0.0 is possible through the Core component, with a CVSS 9.8 vector requiring only HTTP network access and no credentials or user interaction. Successful exploitation yields high confidentiality, integrity, and availability impact, effectively handing the attacker control of the server. No public exploit identified at time of analysis, and no EPSS score was provided; Oracle's October 2026 Critical Patch Update advisory is the authoritative remediation source.

RemediationAI

Patch availability is per the vendor advisory: apply the Oracle Critical Patch Update (October 2026) fixes for Oracle WebLogic Server from https://www.oracle.com/security-alerts/cpuoct2026.html, following the version-specific guidance for 12.2.1.4.0, 14.1.1.0.0, 14.1.2.0.0, and 15.1.1.0.0; the input data does not specify an exact patched version number, so confirm the target release in the advisory before upgrading. If a listed version is out of CPU support, migrate to a supported WebLogic Server release. As compensating controls, restrict network access to the WebLogic HTTP/T3 listeners (commonly 7001/7002) to trusted hosts via firewall or security-group rules, disable the administrative console and T3/IIOP protocol exposure where they are not required, and front the server with a reverse proxy or WAF that can block anomalous pre-authentication requests; these measures reduce reachability but do not remediate the flaw, and disabling T3/IIOP can break clustering or Java client connectivity.

Affected VersionsENISA

Oracle WebLogic Server 14.1.2.0.0
Oracle WebLogic Server 12.2.1.4.0
Oracle WebLogic Server 14.1.1.0.0
Oracle WebLogic Server 15.1.1.0.0

Affected Packages

euvd oracle_weblogic_server no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Oracle WebLogic Server is a Java EE application server whose Core component provides request handling, container services, and administrative endpoints; the flaw is reachable over HTTP by an unauthenticated network attacker (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). The input data does not supply a CWE, so the root-cause class (for example deserialization, authentication bypass, or path traversal) cannot be confirmed, and no CPE strings were provided to narrow the exact module. The vulnerability affects WebLogic Server 12.2.1.4.0, 14.1.1.0.0, 14.1.2.0.0, and 15.1.1.0.0; typical deployments expose HTTP/T3 on ports 7001/7002, but the advisory does not state whether the defect is in the HTTP listener, console, or another Core service. The source tag 'Information Disclosure' is inconsistent with the takeover description and CVSS C/I/A:H impact, so it should not be used to downplay the severity.

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Severity by source

Vendor (oracle) PRIMARY 9.8 CRITICAL
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vuln.today AI 9.8 CRITICAL

Oracle confirms unauthenticated HTTP network exploitation (AV:N/AC:L/PR:N/UI:N) yielding full server takeover, so C:H/I:H/A:H; no cross-system scope change (S:U).

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (oracle).

CVSS VectorVendor: oracle

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

DescriptionCVE.org

Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: Core). Supported versions that are affected are 12.2.1.4.0, 14.1.1.0.0, 14.1.2.0.0 and 15.1.1.0.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle WebLogic Server. Successful attacks of this vulnerability can result in takeover of Oracle WebLogic Server. CVSS 3.1 Base Score 9.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Executive ViewAI

Why It Matters

Oracle WebLogic Server versions 12.2.1.4.0, 14.1.1.0.0, 14.1.2.0.0, and 15.1.1.0.0 are affected by a critical remote takeover flaw that could give an attacker control of the application server. Leadership should care because WebLogic frequently hosts revenue-critical and identity-integrated applications, so a successful compromise could disrupt availability and expose sensitive data across dependent systems. No public exploit identified at time of analysis, but no vendor-released patch is yet available, making exposure management and interim controls the immediate priority.

Business Impact: High
Compensating Controls

No vendor-released patch identified at time of analysis; interim mitigations include restricting network access to WebLogic HTTP interfaces, deploying WAF rules, segmenting affected servers, disabling unused services, and monitoring for anomalous requests until the Oracle October 2026 Critical Patch Update is available.

Threat Intelligence Overview

EPSS Score
0.5%
Top 57% exploitable
Prevalence
High
widely deployed enterprise Java application/middleware server in large organizations
Data Quality
5 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity CRITICAL
CISA KEV No
Public POC No
EPSS 0.5%
Patch available No
Active threat No
Deciding rule
CRITICAL severity
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
Yes
Human Impact
High
Technical Impact
Total

Priority Score

50
Low Medium High Critical
KEV: 0
EPSS: +1
CVSS: +49
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

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