CVE-2025-9823
Reflected XSS in lead:addLeadTags - Quick Add
Published Sep 3, 2025
CVSS 4.0 · 4.8 Medium
EPSS < 1%
KEV · Not listed
Description
SummaryA Cross-Site Scripting (XSS) vulnerability allows an attacker to execute arbitrary JavaScript in the context of another user’s session. This occurs because user-supplied input is reflected back in the server’s response without proper sanitization or escaping, potentially enabling malicious actions such as session hijacking, credential theft, or unauthorized actions in the application.
DetailsThe vulnerability resides in the “Tags” input field on the /s/ajax?action=lead:addLeadTags endpoint. Although the server applies sanitization before storing the data or returning it later, the payload is executed immediately in the victim’s browser upon reflection, allowing an attacker to run arbitrary JavaScript in the user’s session.
ImpactA Reflected XSS attack can have a significant impact, allowing attackers to steal sensitive user data like cookies, redirect users to malicious websites, manipulate the web page content, and essentially take control of a user's session within an application by executing malicious JavaScript code within the victim's browser, even if the server-side code is secure; essentially enabling them to perform actions as if they were the logged-in user.
References * Web Security Academy: Cross-site scripting https://portswigger.net/web-security/cross-site-scripting
* Web Security Academy: Reflected cross-site scripting https://portswigger.net/web-security/cross-site-scripting/reflected
DetailsThe vulnerability resides in the “Tags” input field on the /s/ajax?action=lead:addLeadTags endpoint. Although the server applies sanitization before storing the data or returning it later, the payload is executed immediately in the victim’s browser upon reflection, allowing an attacker to run arbitrary JavaScript in the user’s session.
ImpactA Reflected XSS attack can have a significant impact, allowing attackers to steal sensitive user data like cookies, redirect users to malicious websites, manipulate the web page content, and essentially take control of a user's session within an application by executing malicious JavaScript code within the victim's browser, even if the server-side code is secure; essentially enabling them to perform actions as if they were the logged-in user.
References * Web Security Academy: Cross-site scripting https://portswigger.net/web-security/cross-site-scripting
* Web Security Academy: Reflected cross-site scripting https://portswigger.net/web-security/cross-site-scripting/reflected
Affected Products
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CVE record
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NVD configurations
No data
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Red Hat packages
No data
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OpenCVE enrichment
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mautic | Mautic | unaffected |
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No data.
No data.
| Vendor | Product | Versions |
|---|---|---|
| Mautic | Mautic | — |
Remediation
Tracking
Advisories
| Source | ID | Title |
|---|---|---|
 EUVD |
EUVD-2025-26573 | SummaryA Cross-Site Scripting (XSS) vulnerability allows an attacker to execute arbitrary JavaScript in the context of another user’s session. This occurs because user-supplied input is reflected back in the server’s response without proper sanitization or escaping, potentially enabling malicious actions such as session hijacking, credential theft, or unauthorized actions in the application. DetailsThe vulnerability resides in the “Tags” input field on the /s/ajax?action=lead:addLeadTags endpoint. Although the server applies sanitization before storing the data or returning it later, the payload is executed immediately in the victim’s browser upon reflection, allowing an attacker to run arbitrary JavaScript in the user’s session. ImpactA Reflected XSS attack can have a significant impact, allowing attackers to steal sensitive user data like cookies, redirect users to malicious websites, manipulate the web page content, and essentially take control of a user's session within an application by executing malicious JavaScript code within the victim's browser, even if the server-side code is secure; essentially enabling them to perform actions as if they were the logged-in user. References * Web Security Academy: Cross-site scripting https://portswigger.net/web-security/cross-site-scripting * Web Security Academy: Reflected cross-site scripting https://portswigger.net/web-security/cross-site-scripting/reflected |
 Github GHSA |
GHSA-9v8p-m85m-f7mm | Mautic vulnerable to reflected XSS in lead:addLeadTags - Quick Add |
Metrics
Attack Vector Network
Attack Complexity Low
Privileges Required Low
Attack Requirements None
User Interaction Active
Vulnerable System Confidentiality Impact Low
Vulnerable System Integrity Impact Low
Vulnerable System Availability Impact None
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
No CVSS v3.1
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.317% probability within 30 days)
Exploitation none
Automatable no
Technical Impact partial
References
History
Sep 3, 2025 7:45 PM
First appearance in the feed. Affected vendors updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Mautic
Mautic mautic |
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| Vendors & Products |
Mautic
Mautic mautic |
Sep 3, 2025 6:15 PM
Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Sep 3, 2025 2:45 PM
Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | SummaryA Cross-Site Scripting (XSS) vulnerability allows an attacker to execute arbitrary JavaScript in the context of another user’s session. This occurs because user-supplied input is reflected back in the server’s response without proper sanitization or escaping, potentially enabling malicious actions such as session hijacking, credential theft, or unauthorized actions in the application. DetailsThe vulnerability resides in the “Tags” input field on the /s/ajax?action=lead:addLeadTags endpoint. Although the server applies sanitization before storing the data or returning it later, the payload is executed immediately in the victim’s browser upon reflection, allowing an attacker to run arbitrary JavaScript in the user’s session. ImpactA Reflected XSS attack can have a significant impact, allowing attackers to steal sensitive user data like cookies, redirect users to malicious websites, manipulate the web page content, and essentially take control of a user's session within an application by executing malicious JavaScript code within the victim's browser, even if the server-side code is secure; essentially enabling them to perform actions as if they were the logged-in user. References * Web Security Academy: Cross-site scripting https://portswigger.net/web-security/cross-site-scripting * Web Security Academy: Reflected cross-site scripting https://portswigger.net/web-security/cross-site-scripting/reflected | |
| Title | Reflected XSS in lead:addLeadTags - Quick Add | |
| Weaknesses | CWE-79 | |
| References |
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| Metrics |
cvssV4_0
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Weaknesses
