VulnerabilityPublished 20 Jan 2026

CVE-2026-21966: 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.

Affects Oracle Hospitality OPERA 5 Property ServicesSource CVE Database V5

Not known to be exploited · CVSS 6.1 Medium.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score

6.1Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Changed
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Oracle CorporationOracle Hospitality OPERA 5 Property Services	Affected 5.6.19.23 – 5.6.27.4 4 affected builds	Fixed in–
Mavencom.oracle.hospitality/opera5-property-services`pkg:maven/com.oracle.hospitality/opera5-property-services`Other threats	Affected 5.6.19.23 – 5.6.27.4 4 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Apply official patches or updates from Oracle as soon as they become available for the affected OPERA 5 versions to remediate the vulnerability.
Restrict network access to Oracle Hospitality OPERA 5 Property Services interfaces, limiting exposure to trusted internal networks and blocking unnecessary HTTP access from external or untrusted sources.
Implement strict network segmentation to isolate OPERA 5 systems from general corporate networks and the internet.
Enhance user awareness training focused on social engineering and phishing risks, emphasizing caution when interacting with unexpected requests or links, as exploitation requires human interaction.
Monitor logs and network traffic for unusual activities indicative of exploitation attempts, such as unauthorized data modification or access patterns.
Employ multi-factor authentication (MFA) where possible on systems interacting with OPERA 5 to reduce the risk of unauthorized access.
Conduct regular security assessments and penetration testing on hospitality systems to identify and remediate other potential vulnerabilities.
Review and tighten access controls within OPERA 5 to ensure least privilege principles are enforced, minimizing the impact of any unauthorized access.
Maintain an incident response plan tailored to hospitality sector threats, enabling rapid containment and recovery if exploitation occurs.

Description

CVE-2026-21966 is a medium-severity vulnerability in Oracle Hospitality OPERA 5 Property Services versions 5.6.19.23, 5.6.25.17, 5.6.26.10, and 5.

Impact

For European organizations, especially those in the hospitality sector using Oracle Hospitality OPERA 5, this vulnerability could lead to unauthorized access and manipulation of sensitive guest and operational data. Confidentiality breaches could expose personal guest information, while integrity compromises could result in altered reservation details, billing information, or operational data, potentially disrupting business processes and damaging reputation. Although availability is not impacted, the unauthorized data modifications could cause operational inefficiencies and financial losses. The requirement for human interaction suggests phishing or social engineering could be vectors, increasing risk in environments with less user security awareness. The scope change indicates that exploitation could affect other integrated Oracle Hospitality products, broadening the impact. European hospitality organizations are often subject to strict data protection regulations such as GDPR, so data breaches could also result in regulatory penalties and legal consequences. The vulnerability's network accessibility via HTTP increases exposure, especially if systems are accessible from less secure networks or the internet. Overall, the threat could undermine trust in hospitality services and lead to financial and reputational damage.

References

oracle.com/security-alerts/cpujan2026.html (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 28 Jan 2026, 20:24 UTC

Technical details

References

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