Security readout for executives and security teams
Plain-English summary
CVE-2026-21966 affects Oracle Hospitality OPERA 5 Property Services, used in hospitality property operations. An unauthenticated network attacker can trigger it over HTTP, but a separate user must interact. Impact is limited data reading and data modification, with potential effects beyond the vulnerable component.
Executive priority
Treat as a near-term remediation item for hospitality environments using affected OPERA versions, especially if accessible beyond tightly controlled networks. It is not currently evidenced as actively exploited, but it can affect reservation or property-service data integrity and confidentiality.
Technical view
Oracle reports affected OPERA 5 Property Services versions 5.6.19.23, 5.6.25.17, 5.6.26.10, and 5.6.27.4. CVSS is 6.1: network exploitable, low complexity, no privileges, user interaction required, scope changed, low confidentiality and integrity impact, no availability impact.
Likely exposure
Exposure is most relevant where affected OPERA 5 Property Services versions are reachable over HTTP by untrusted or broad internal networks. Internet exposure would increase urgency, but the provided sources do not confirm typical deployment exposure.
Exploitation context
The sources do not report active exploitation, and this CVE is not marked KEV in the provided bundle. Exploitation requires network access via HTTP and human interaction by someone other than the attacker.
Researcher notes
The public description does not identify the weakness class or vulnerable endpoint. Avoid assuming exploit mechanics. Focus validation on version confirmation, HTTP exposure, user-interaction paths, and evidence of unauthorized data read or modification. Oracle’s CPU is the primary remediation source.
Mitigation direction
- Identify whether OPERA 5 Property Services is deployed.
- Check for affected versions: 5.6.19.23, 5.6.25.17, 5.6.26.10, 5.6.27.4.
- Review Oracle January 2026 CPU guidance for remediation instructions.
- Restrict HTTP access to trusted networks where business operations allow.
- Increase monitoring for unusual OPERA data reads or modifications.
Validation and detection
- Inventory OPERA 5 Property Services instances and versions.
- Confirm whether HTTP endpoints are reachable from untrusted networks.
- Verify Oracle CPU remediation status for each affected instance.
- Review access logs for suspicious unauthenticated HTTP activity.
- Check application records for unexpected data updates, inserts, deletes, or reads.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2026-21966 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N2.82.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- Oracle AdvisoryCVE reference · vendor-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.