dbcve.org
Hospitality Opera 5Application · Oracle

CVE-2026-21966

MEDIUM · 6.1 CVSS v3.1 Published 2026-01-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Vulnerability in the Oracle Hospitality OPERA 5 Property Services product of Oracle Hospitality Applications (component: Opera). Supported versions that are affected are 5.6.19.23, 5.6.25.17, 5.6.26.10 and 5.6.27.4. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle Hospitality OPERA 5 Property Services. Successful attacks require human interaction from a person other than the attacker and while the vulnerability is in Oracle Hospitality OPERA 5 Property Services, attacks may significantly impact additional products (scope change). Successful attacks of this vulnerability can result in unauthorized update, insert or delete access to some of Oracle Hospitality OPERA 5 Property Services accessible data as well as unauthorized read access to a subset of Oracle Hospitality OPERA 5 Property Services accessible data. CVSS 3.1 Base Score 6.1 (Confidentiality and Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N).

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Unauthenticated HTTP vulnerability in Oracle Hospitality OPERA 5 Property Services allowing remote attackers to read and modify a subset of data without credentials. Requires human interaction (likely clickjacking or CSRF-style attack). The scope change indicates the vulnerability can be leveraged to affect additional products beyond the directly affected component.

MitigationApply Oracle's patched versions when released. Implement WAF rules for suspicious HTTP patterns, enforce CSRF protections, and restrict network access to the OPERA 5 Property Services interface.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Hospitality Opera 5Application
Affected:= 5.6.19.23= 5.6.25.17= 5.6.26.10= 5.6.27.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Oracle Hospitality OPERA 5 installation
    Check for OPERA 5 processes or services running on the system. Look for 'OPERA' or 'Oracle Hospitality' in running services, or check installation directories such as C:\Oracle\OPERA or /opt/oracle/opera if on Linux/Unix.
    Affected if Oracle Hospitality OPERA 5 software is present on the system
  2. Determine installed OPERA 5 version
    Locate the version information in the OPERA installation. Common locations include the About dialog in the application, version.txt or ver.txt files in the installation directory, or the Windows Registry under HKLM\SOFTWARE\Oracle\OPERA. Compare the version number to 5.6.19.23, 5.6.25.17, 5.6.26.10, or 5.6.27.4.
    Affected if The installed version matches exactly 5.6.19.23, 5.6.25.17, 5.6.26.10, or 5.6.27.4
  3. Verify Property Services HTTP interface is exposed
    Check if the OPERA 5 Property Services web interface is accessible over HTTP. Common ports include 8080, 8000, or 80/443 configured for OPERA. Use netstat or port scanning tools to identify listening HTTP services on these ports, then attempt to access the Property Services endpoint via browser or curl command.
    Affected if The Property Services HTTP interface is reachable over the network
  4. Confirm unauthenticated HTTP endpoints are accessible
    Attempt to access common OPERA Property Services endpoints without authentication credentials. Try accessing URLs such as /opera/property or the application's login page over HTTP. If the application responds without requiring authentication, the system may be vulnerable.
    Affected if HTTP requests to Property Services return responses without requiring authentication

The environment is affected if Oracle Hospitality OPERA 5 is installed with version 5.6.19.23, 5.6.25.17, 5.6.26.10, or 5.6.27.4 and the Property Services HTTP interface is network-accessible without authentication.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply Oracle's patched versions when released. Implement WAF rules for suspicious HTTP patterns, enforce CSRF protections, and restrict network access to the OPERA 5 Property Services interface.

Recommended fix Moderate confidence
  1. Contact Oracle Support to request the patch for CVE-2026-21966 for Oracle Hospitality OPERA 5 Property Services.
  2. Navigate to Oracle Support website and search for Oracle Hospitality OPERA 5 patches or Critical Patch Updates.
  3. Apply the Oracle-provided patch following the documentation supplied with the patch.
  4. After patching, verify the vulnerability is resolved by testing the affected HTTP endpoints.
  5. Confirm that human interaction is still required for exploitation (as designed) and that unauthorized data access is now prevented.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Hospitality Opera 5 Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA6.0 h
42.0 hours of engineering $7,360
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-21966 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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