VulnerabilityPublished 21 Jul 2025Updated 22 Jul 2025

CVE-2025-51398: A Stored Cross-site Scripting (XSS)

Source CVE Database V5

Public exploit available (Exploit-DB) · CVSS 5.4 Medium.

Data as of 26 Oct 2026, 11:42 UTC

CVSS 3.1 base score

5.4Medium

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

EPSS: 0.9% chance of exploitation in 30 days – higher than 61% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/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

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 21 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
1 Exploit-DB entry, 1 day after disclosure
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

CVE ID reserved
by MITRE Corporation
16 Jun 2025, 35 days before disclosure
CVE published
on cve.org
21 Jul 2025, t = 0
In Threat Radar
record ingested
21 Jul 202519:01 UTC, the same day as disclosure
First Exploit-DB entry (opens in a new tab)
LiveHelperChat 4.61 - Stored Cross Site Scripting (XSS) via Facebook Integration Page Name Field
22 Jul 2025, 1 day after disclosure

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

AI-suggested

Organizations should immediately assess their use of Live Helper Chat and determine if version 4.60 or earlier is deployed. Until an official patch is available, mitigation should include implementing strict input validation and output encoding on the 'Name' parameter at the application or web server level to neutralize malicious scripts. Web Application Firewalls (WAFs) can be configured to detect and block typical XSS payloads targeting the registration page. Additionally, enforcing multi-factor authentication and monitoring user registrations for suspicious activity can reduce risk. User education to recognize phishing or suspicious chat content is also advisable. Organizations should plan to upgrade to a patched version once released and conduct thorough security testing of chat interfaces. Logging and alerting on anomalous input patterns can help detect exploitation attempts early. Finally, reviewing and tightening Content Security Policy (CSP) headers can limit the impact of any successful XSS payloads.

Description

A stored cross-site scripting (XSS) vulnerability in the Facebook registration page of Live Helper Chat v4.60 allows attackers to execute arbitrary web scripts or HTML via injecting a crafted payload into the Name parameter.

Impact

For European organizations using Live Helper Chat v4.60, this vulnerability could lead to unauthorized disclosure of user data, session hijacking, and potential manipulation of chat interactions. Given that Live Helper Chat is often deployed by businesses for customer support, exploitation could undermine customer trust and lead to reputational damage. Confidentiality breaches could expose personal data protected under GDPR, leading to regulatory penalties. Integrity impacts could allow attackers to inject misleading or malicious content into chat sessions, potentially facilitating social engineering attacks or spreading malware. The requirement for some level of authentication and user interaction limits the ease of exploitation but does not eliminate risk, especially in environments with many users or where attackers can create accounts. The absence of a patch at the time of publication increases exposure. European organizations with customer-facing chat services are particularly at risk, especially those in regulated sectors such as finance, healthcare, and e-commerce where data protection is critical.

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation · Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide…
OWASP Cheat Sheets
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.3 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
DOM-Based XSS (opens in a new tab)
Reflected XSS (opens in a new tab)
Stored XSS (opens in a new tab)
Cross-Site Scripting (XSS) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

Timeline

What to do

Description

AI analysisMachine-generated, updated 29 Jul 2025, 01:28 UTC

Public exploits and detection1 Exploit-DB entry

WeaknessesCWE-79

Technical details

References

Community reviews

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