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Hospitality Opera 5Application · Oracle

CVE-2026-21967

HIGH · 8.6 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 →
95/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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 product of Oracle Hospitality Applications (component: Opera Servlet). 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. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Oracle Hospitality OPERA 5 accessible data as well as unauthorized update, insert or delete access to some of Oracle Hospitality OPERA 5 accessible data and unauthorized ability to cause a partial denial of service (partial DOS) of Oracle Hospitality OPERA 5. CVSS 3.1 Base Score 8.6 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L).

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 · high confidence

Unauthenticated HTTP vulnerability in the Opera Servlet component of Oracle Hospitality OPERA 5 allows remote attackers to gain unauthorized access to critical data, perform some data modifications (insert/update/delete), and cause partial denial of service. The flaw affects versions 5.6.19.23, 5.6.25.17, 5.6.26.10, and 5.6.27.4.

MitigationApply the Oracle Critical Patch Update for CVE-2026-21967 to the affected OPERA 5 versions. If immediate patching is not possible, restrict network access to the Opera Servlet endpoints via firewall or web application firewall rules.

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
None
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
Low

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

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 OPERA 5 version
    Locate the Oracle Hospitality OPERA 5 installation and retrieve the installed version number. This is typically found in the application properties, version file, or about screen within the OPERA administrative interface.
    Affected if The installed version matches 5.6.19.23, 5.6.25.17, 5.6.26.10, or 5.6.27.4 exactly.
  2. Verify Opera Servlet is enabled
    Confirm that the Opera Servlet component is deployed and enabled in the OPERA 5 application server. Check the application server configuration for servlet mappings related to Opera Servlet.
    Affected if The Opera Servlet component is present and active in the application configuration.
  3. Check HTTP exposure of Opera Servlet
    Determine if the Opera Servlet is accessible via HTTP/HTTPS from the network. Review web server or application server configuration for servlet URL mappings (typically under /servlet/ or similar paths) and verify network accessibility.
    Affected if The Opera Servlet endpoint is reachable over HTTP/HTTPS from network locations, especially untrusted networks.

You are affected if your Oracle Hospitality OPERA 5 installation is version 5.6.19.23, 5.6.25.17, 5.6.26.10, or 5.6.27.4 AND the Opera Servlet component is network-accessible via HTTP.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the Oracle Critical Patch Update for CVE-2026-21967 to the affected OPERA 5 versions. If immediate patching is not possible, restrict network access to the Opera Servlet endpoints via firewall or web application firewall rules.

Fix this in Hospitality Opera 5 Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing24.0 h
  • Review / QA8.0 h
56.0 hours of engineering $9,520
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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-2026-21967 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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