CVE-2025-9823: Mautic/core AddLeadTags - Quick Add Vulnerability
MODERATECVE-2025-9823 is a MODERATE addleadtags - quick add vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Mautic/core libraries in the Packagist ecosystem. The issue involves addleadtags - quick add. Remediation is available by upgrading affected packages to version 4.4.17, 5.2.8, 6.0.5.
CVE-2025-9823 at a Glance
How to Fix CVE-2025-9823
To remediate this vulnerability, upgrade all affected Mautic/core dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade mautic/core to 4.4.17Upgrade mautic/core to 5.2.8Upgrade mautic/core to 6.0.5Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for mautic/coreHow to Check if You Are Affected
To determine whether your application is affected by CVE-2025-9823, inspect your project dependencies for Mautic/core:
inspect dependencies for mautic/coreAnalyze the terminal output to locate any version of Mautic/core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.4.17), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where 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. In Mautic/core, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2025-9823 Affected Mautic/core Versions
3 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
mautic/core
|
Packagist |
≥ 4.4.0
< 4.4.17
|
4.4.17
|
|
mautic/core
|
Packagist |
≥ 5.0.0-alpha
< 5.2.8
|
5.2.8
|
|
mautic/core
|
Packagist |
≥ 6.0.0-alpha
< 6.0.5
|
6.0.5
|
References
Frequently Asked Questions
What is CVE-2025-9823?
Which Mautic/core versions are affected?
What version fixes CVE-2025-9823?
Is mautic/core affected?
What CWE is associated with CVE-2025-9823?
How can I check Packagist dependencies for CVE-2025-9823?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-9v8p-m85m-f7mm",
"modified" : "2025-09-03T22:18:39Z",
"published" : "2025-09-03T22:18:39Z",
"aliases" : [ "CVE-2025-9823" ],
"summary" : "Mautic vulnerable to reflected XSS in lead:addLeadTags - Quick Add",
"details" : "## Summary\n\nA 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.\n\n## Details\n\nThe 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.\n\n## Impact\nA 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.\n\n## References\n- [Web Security Academy: Cross-site scripting](https://portswigger.net/web-security/cross-site-scripting)\n- [Web Security Academy: Reflected cross-site scripting](https://portswigger.net/web-security/cross-site-scripting/reflected)",
"severity" : [ {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Packagist",
"name" : "mautic/core"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "4.4.0"
}, {
"fixed" : "4.4.17"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Packagist",
"name" : "mautic/core"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "5.0.0-alpha"
}, {
"fixed" : "5.2.8"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Packagist",
"name" : "mautic/core"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "6.0.0-alpha"
}, {
"fixed" : "6.0.5"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/mautic/mautic/security/advisories/GHSA-9v8p-m85m-f7mm"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-9823"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/mautic/mautic"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-79" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2025-09-03T22:18:39Z",
"nvd_published_at" : "2025-09-03T15:15:49Z"
}
}