Medium

CVE-2026-21966 — Vulnerability in the Oracle Hospitality OPERA 5 Property Services product of Oracle…

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).

Published Jan 20, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: oracle

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+2
Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.22%

ahead of 11% of scored CVEs · Oct 14, 2026

Affects

Oracle

Hospitality Opera 5 and 1 more

CVSS base

6.1

Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Oracle Hospitality Opera 5, Oracle Hospitality Opera 5 Property Services).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Exploitation requires user interaction: tighten email/web filtering and warn affected users.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Oracle	Hospitality Opera 5	version 5.6.19.23version 5.6.25.17version 5.6.26.10version 5.6.27.4	Vulnerable	NIST National Vulnerability Database
Oracle	Hospitality Opera 5 Property Services	version 5.6.19.23version 5.6.25.17version 5.6.26.10version 5.6.27.4	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
6.1	CVSS 3.1	Medium	2.8	2.7	secalert_us@oracle.com via NIST National Vulnerability Database
6.1	CVSS 3.1	Medium	—	—	oracle via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N (score shown at the top: secalert_us@oracle.com)

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.22%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · oracle corporation/oracle hospitality opera 5 property services
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 6.1
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Jan 20, 2026 · oracle

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

1 on the record

www.oracle.com/security-alerts/cpujan2026.html
Vendor Advisory, vendor-advisory, NIST National Vulnerability Database

Elsewhere on this site

Oracle
every CVE for this vendor

Related CVEs (same products)

High CVE-2026-71106 Improper Access Control in Oracle Hospitality Opera 5 Property Services Aug 18, 2026
Critical CVE-2026-34311 Vulnerability in the Oracle Hospitality OPERA 5 Property Services product of Oracle Hospitality... May 28, 2026
High CVE-2026-21967 Vulnerability in the Oracle Hospitality OPERA 5 product of Oracle Hospitality… Jan 20, 2026
Critical CVE-2020-17530 Apache Struts Remote Code Execution Vulnerability KEV Dec 10, 2020
Medium CVE-2020-17521 Apache Groovy provides extension methods to aid with creating temporary directories… Dec 7, 2020
Medium CVE-2019-10219 Cross-site Scripting (XSS) in Red Hat Hibernate Validator Nov 8, 2019

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-21966 is "Vulnerability in the Oracle Hospitality OPERA 5 Property Services product of Oracle…", rated Medium. It affects Hospitality Opera 5 (Oracle); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.1 describes technical severity. EPSS 0.22% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

Comments

Moderated technical discussion. Read the community guidelines.

No comments yet.