CVE-2026-83093

Executive Summary

CVE-2026-83093 is an easily exploitable, unauthenticated information-disclosure vulnerability in the Forms Services (including C/S and Charmode) component of Oracle Forms, a Core product of Oracle Fusion Middleware. Supported affected releases are 12.2.1.19.0 and 14.1.2.0.0. A remote attacker with network access via HTTP can compromise Oracle Forms without authentication and obtain unauthorized access to critical data or complete read access to all data accessible through the Oracle Forms deployment (CVSS 3.1 Base Score 8.6, Confidentiality High, Scope Changed). No public proof-of-concept, exploit code, or Nuclei template is currently available, and the vulnerability is not listed in CISA KEV.

Technical Analysis

Oracle Forms is an enterprise application-development and runtime platform delivered as part of Oracle Fusion Middleware. The affected component per the NVD description is "Forms Services, C/S, Charmode." Forms Services is the server-side tier (typically running in a Java EE container such as Oracle WebLogic Server) that services Forms client requests over HTTP/HTTPS. "C/S" refers to the client/server deployment model, and "Charmode" refers to the character-mode (terminal) client presentation mode.

The vulnerability is classified from the CVSS vector as a network-reachable (AV:N), low-complexity (AC:L), no-privileges-required (PR:N), no-user-interaction (UI:N) issue with a Scope Change (S:C) and High Confidentiality impact (C:H), but no Integrity (I:N) or Availability (A:N) impact. The specific mechanism that permits unauthenticated data disclosure is not detailed in the NVD description. The Scope Change indicates that while the flaw resides in Oracle Forms, exploitation can impact resources beyond the vulnerable component's security authority — i.e., the attacker may read data belonging to other products or trust boundaries that the Forms deployment can reach (e.g., database sessions, integrated Fusion Middleware components, or connected downstream applications).

At the vulnerability-class level, this is best characterized as improper access control / missing authentication or authorization enforcement on a Forms Services request path that exposes data. The low attack complexity and lack of required privileges indicate the flaw is reachable by simply sending a crafted HTTP request to a Forms Services endpoint — no credentials, session, or user action is required. Insufficient technical detail is available in the provided description to identify the exact HTTP endpoint, parameter, or code routine involved; per accuracy constraints, no specific function names, API paths, or parameters are asserted here.

Attack surface: any Oracle Forms 12.2.1.19.0 or 14.1.2.0.0 deployment that is reachable over HTTP from an untrusted network. Because Oracle Forms is frequently internet-exposed or exposed to broad internal networks to support thin-client and character-mode access, this constitutes a meaningful external attack surface when not placed behind strong network controls.

Exploitation Scenarios

No public PoC is available; the following attack chain is inferred strictly from the vulnerability class (unauthenticated network-reachable information disclosure in Oracle Forms Forms Services) and the provided CVSS data.

1. Reconnaissance / target identification: An unauthenticated attacker with network access identifies internet- or intranet-reachable Oracle Forms instances. This is done by fingerprinting HTTP responses and static resources associated with Forms Services (for example, Forms servlet paths and Forms-specific MIME types). Shodan-style discovery using product/title/HTML signatures ("Oracle Forms", Forms login/launch pages) narrows the target set.

2. Triggering the flaw: With no authentication required (PR:N) and no user interaction (UI:N), the attacker sends a crafted HTTP request directly to a Forms Services endpoint that fails to enforce proper access control. Because the flaw is low-complexity (AC:L), this is a single-shot, direct request — no chained preconditions or timing tricks are needed. The exact request format is not specified in the available data and is not fabricated here.

3. Payload/execution method: At the vulnerability-class level, the "payload" is a request that causes the server to return data the requester is not authorized to access. This is an improper-access-control / unauthenticated-read class of flaw rather than a memory-corruption or command-execution flaw; there is no code execution or file write implied by the CVSS vector (I:N, A:N).

4. Post-exploitation impact: Successful exploitation results in unauthorized access to critical data or complete access to all Oracle Forms-accessible data (C:H). With Scope Change (S:C), the impact extends beyond the Forms component itself — potentially to integrated systems or data the Forms tier can reach. There is no integrity or availability impact, meaning the flaw is a read/exfiltration primitive rather than a destructive or persistence-enabling one by itself. However, disclosed data can enable follow-on attacks (credential reuse, session hijacking, or lateral movement) using the information obtained.

Impact Assessment

Business impact is high for confidentiality. Oracle Forms commonly fronts business-critical, regulated, and financial data through forms-based workflows; a high-confidentiality, unauthenticated read flaw can result in large-scale exposure of that data. CVSS subscores:

• Attack Vector: Network (AV:N) — remotely exploitable.
• Attack Complexity: Low (AC:L) — no specialized conditions.
• Privileges Required: None (PR:N) — no account needed.
• User Interaction: None (UI:N) — no victim action.
• Scope: Changed (S:C) — impact can cross security boundaries to other products.
• Confidentiality: High (C:H); Integrity: None (I:N); Availability: None (A:N).
• Base Score: 8.6.

Blast radius: every reachable Oracle Forms 12.2.1.19.0 and 14.1.2.0.0 deployment. Because Scope is Changed, assess not just Forms but connected Fusion Middleware components and downstream data stores. EPSS is not yet scored by FIRST.org, so exploit-likelihood weighting is currently unavailable. CISA KEV status: NOT listed.

Detection Guidance

Sigma Rule

title: Potential Oracle Forms CVE-2026-83093 Unauthenticated Information Disclosure
id: 8f7a1c20-3e4b-4d9a-9b2e-oracleforms83093
status: experimental
description: Detects anomalous unauthenticated HTTP requests to Oracle Forms Forms Services endpoints that may indicate exploitation of CVE-2026-83093.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-83093
author: valtersit.com
date: 2026/01/01
tags:
  - attack.initial_access
  - attack.t1190
logsource:
  category: webserver
  product: oracle
detection:
  selection_method:
    cs-method:
      - GET
      - POST
  selection_forms:
    cs-uri-stem|contains:
      - '/forms/'
      - 'FormsServlet'
      - 'frmservlet'
  selection_unauth:
    sc-status:
      - 200
  condition: selection_method and selection_forms and selection_unauth
falsepositives:
  - Legitimate unauthenticated Forms login/launch pages
level: medium

YARA Rule

rule EXPL_OracleForms_CVE_2026_83093_AccessControl
{
    meta:
        description = "Detects indicators of Oracle Forms unauthenticated information disclosure abuse (CVE-2026-83093) in HTTP logs or captured traffic"
        author = "valtersit.com"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-83093"
        date = "2026-01-01"
        severity = "high"
    strings:
        $forms1 = "FormsServlet" ascii nocase
        $forms2 = "frmservlet" ascii nocase
        $forms3 = "/forms/" ascii nocase
        $auth = "Authorization:" ascii nocase
        $cookie = "JSESSIONID" ascii nocase
    condition:
        any of ($forms*) and not ($auth) and filesize < 64KB
}

Suricata IDS Rule

alert http any any -> any any (msg:"EXPLOIT Oracle Forms CVE-2026-83093 Unauthenticated Information Disclosure Attempt"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"FormsServlet"; nocase; sid:8309301; rev:1; metadata:created_at 2026_01_01, cve CVE_2026_83093; classtype:attempted-recon; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-83093;)

Elastic Detection

network where
  http.request.method in ("GET", "POST") and
  (
    stringContains(http.request.uri, "FormsServlet") or
    stringContains(http.request.uri, "/forms/") or
    stringContains(http.request.uri, "frmservlet")
  ) and
  http.response.status_code == 200 and
  not (http.request.headers contains "Authorization" or
       http.request.headers contains "JSESSIONID")

Splunk SPL Query

index=web sourcetype=access_combined OR sourcetype=access_common
| search (uri_path="*FormsServlet*" OR uri_path="*/forms/*" OR uri_path="*frmservlet*")
| eval unauth = if((isnull(cookie) OR cookie="") AND (isnull(referer) OR referer=""), 1, 0)
| where unauth=1 AND status=200
| stats count values(uri_path) as paths by src_ip, host
| where count > 5
| sort - count

Wazuh OSSEC Rule

<group name="web,oracle_forms,">
  <rule id="830930" level="10">
    <if_sid>31100</if_sid>
    <url>FormsServlet|/forms/|frmservlet</url>
    <description>CVE-2026-83093: Possible unauthenticated Oracle Forms information disclosure attempt</description>
    <mitre>
      <id>T1190</id>
    </mitre>
    <group>attack,pci_dss_6.5,waf,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source).

1. Immediate mitigations:

• Restrict network access to Oracle Forms Forms Services. Do not expose Forms Services (C/S, Charmode) to untrusted networks; enforce allowlisting at the firewall/WAF/reverse proxy layer.
• Apply virtual patching at the WAF/proxy to block unauthenticated requests to Forms Services endpoints that are not required for legitimate pre-authentication flows.
• Enforce strong authentication and session handling at the perimeter (mutual TLS, authenticated reverse proxy) so that requests reaching Forms Services are already authenticated.
• Monitor and alert on unauthenticated HTTP 200 responses from Forms Services endpoints (see detection guidance).

2. Patch/upgrade steps:

• Oracle has not, per the tracked data, published a patch reference for CVE-2026-83093. Monitor Oracle's Critical Patch Update (CPU) and Security Alert advisories for Oracle Forms / Oracle Fusion Middleware for the corresponding fix.
• When a fix version is released, upgrade affected 12.2.1.19.0 and 14.1.2.0.0 installations to the patched release and validate Forms Services functionality.

3. Long-term hardening:

• Apply the principle of least exposure: keep Forms Services behind authenticated proxies and network segmentation; treat the Forms tier as a high-value target.
• Adopt a continuous vulnerability-management process tied to Oracle CPU releases; this CVE is currently UNPATCHED, so compensating controls are mandatory in the interim.
• Review data reachable from the Forms tier, given the Scope Changed rating, and reduce unnecessary cross-system access from Forms Services.
• Retire unsupported or legacy deployment modes (C/S, Charmode) where operationally feasible, as they may widen the attack surface.

References

• NVD — CVE-2026-83093: https://nvd.nist.gov/vuln/detail/CVE-2026-83093
• Oracle Critical Patch Updates and Security Alerts (monitor for Oracle Forms / Fusion Middleware fixes): https://www.oracle.com/security-alerts/
• FIRST EPSS (not yet scored at time of writing): https://www.first.org/epss/
• CISA Known Exploited Vulnerabilities Catalog (CVE-2026-83093 is NOT listed): https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• MITRE ATT&CK T1190 — Exploit Public-Facing Application: https://attack.mitre.org/techniques/T1190/

Note on exploit evidence: No public proof-of-concept, Nuclei template, or exploit code is available for CVE-2026-83093 in the provided data, and no threat-actor campaign or in-the-wild exploitation has been reported. All detection content is derived from the vulnerability class (unauthenticated network-reachable information disclosure in Oracle Forms Forms Services) and must be tuned to the target environment.