CVE-2025-53504VulnerabilityPublished 21 Aug 2025

CVE-2025-53504: Intermesh BV Group-Office · Cross-site scripting (XSS)

Affects Intermesh BV Group-OfficeSource CVE Database V5

Not known to be exploited · CVSS 5.4 Medium : upgrade to 6.8.119 when convenient.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.0 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 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 6.8.119

CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
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 21 Aug 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 2026-10-25.

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

Upgrade Intermesh BV Group-Office to 6.8.119.

Affected software

Product	Affected	Fixed in
Intermesh BV Group-Office	Affected <6.8.119	Fixed in 6.8.119

AI-suggested

Organizations should prioritize upgrading Group-Office installations to version 6.8.119 or later, where the vulnerability is patched. In the absence of immediate patching, administrators should implement strict input validation and output encoding on all user-supplied data within the application, especially in areas exposed to user input. Employing Content Security Policy (CSP) headers can help mitigate the impact of XSS by restricting the execution of unauthorized scripts. User awareness training to recognize phishing and suspicious links can reduce the likelihood of user interaction with malicious payloads. Additionally, monitoring web application logs for unusual input patterns and anomalous user behaviors can help detect attempted exploitation. Network-level protections such as web application firewalls (WAFs) configured to detect and block XSS payloads can provide an additional layer of defense. Regular security assessments and penetration testing focused on web application vulnerabilities are recommended to identify and remediate similar issues proactively.

Description

Group-Office versions prior to 6.8.119 and prior to 25.0.20 provided by Intermesh BV contain a cross-site scripting vulnerability. If this vulnerability is exploited, an arbitrary script may be executed in the user's web browser.

Impact

For European organizations using Group-Office, this vulnerability poses a risk of client-side attacks that could compromise user sessions and data confidentiality. Since Group-Office is used for collaboration and communication, successful exploitation could lead to unauthorized access to sensitive corporate information, internal communications, and project data. The requirement for user interaction (e.g., clicking a malicious link) somewhat limits the attack vector but does not eliminate risk, especially in environments where phishing attacks are common. The vulnerability's medium severity suggests that while it is not critical, it could be leveraged as part of a multi-stage attack chain. European organizations in sectors such as finance, government, healthcare, and legal services, which rely heavily on secure collaboration tools, could face reputational damage, regulatory penalties under GDPR for data breaches, and operational disruptions if attackers exploit this vulnerability to escalate privileges or exfiltrate data.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 21 Aug 2025, 04:47 UTC

Technical details

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