VulnerabilityPublished 27 Nov 2025Updated 1 Dec 2025

CVE-2025-59026: Open-Xchange OX App Suite · Cross-site Scripting

Affects Open-Xchange OX App SuiteSource CVE Database V5

Not known to be exploited · CVSS 5.4 Medium.

Data as of 26 Oct 2026, 09:15 UTC

CVSS 3.1 base score

5.4Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% 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:U/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
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: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
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 27 Nov 2025
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 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
Open-Xchange GmbH OX App Suite	Affected =0	Fixed in–

AI-suggested

European organizations should immediately monitor for vendor patch releases and apply them without delay. In the interim, implement strict input validation and output encoding on file upload and web page rendering components if possible. Employ Content Security Policy (CSP) headers to restrict script execution sources and reduce XSS impact. Educate users to recognize and avoid suspicious links, especially those received via email or messaging platforms. Use web application firewalls (WAFs) with updated signatures to detect and block exploitation attempts. Conduct regular security assessments and penetration tests focusing on web application input handling. Review and tighten access controls and session management to limit the damage from potential XSS exploitation. Maintain comprehensive logging and monitoring to detect anomalous user activity indicative of exploitation.

Description

Malicious content uploaded as file can be used to execute script code when following attacker-controlled links. Unintended actions can be executed in the context of the users account, including exfiltration of sensitive information. Please deploy the provided updates and patch releases. No publicly available exploits are known

Impact

For European organizations using OX App Suite, this vulnerability could lead to unauthorized access to sensitive corporate or personal data, undermining confidentiality and user trust. Attackers exploiting this XSS flaw could hijack user sessions, perform unauthorized actions, or exfiltrate data, potentially leading to data breaches or compliance violations under GDPR. Given the SaaS and hosted nature of OX App Suite deployments, the impact could extend to multiple users and departments within an organization. The requirement for user interaction limits automated exploitation but does not eliminate risk, especially in phishing or social engineering scenarios. Disruption of user workflows and reputational damage are additional concerns. The medium severity rating suggests a moderate but actionable threat that should be addressed promptly to avoid escalation or chaining with other vulnerabilities.

Summary

CVE-2025-59026 is a cross-site scripting (XSS) vulnerability identified in the OX App Suite developed by Open-Xchange GmbH. The root cause is improper neutralization of input during web page generation, specifically when malicious content is uploaded as a file. When a user clicks on a crafted link controlled by an attacker, the embedded script executes in the context of the victim’s browser session. This allows the attacker to perform actions on behalf of the user, such as accessing or exfiltrating sensitive information stored within the application. The vulnerability does not require authentication or elevated privileges but does require user interaction (clicking the malicious link). The CVSS v3.1 base score is 5.4, reflecting medium severity with network attack vector, low attack complexity, no privileges required, and user interaction needed. Although no public exploits are currently known, the vulnerability poses a tangible risk due to the widespread use of OX App Suite in enterprise and service provider environments. The vendor has released updates and patches to remediate the issue, emphasizing the need for timely deployment to prevent exploitation.

References

documentation.open-xchange.com/appsuite/security/advisories/csaf/2025/oxas-adv-2025-0003.json (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Dec 2025, 11:07 UTC

Technical details

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