Cross-site scripting in Mautic - CVE-2025-9823
Published: May 25, 2026
Vulnerability identifier: #VU132234
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2025-9823
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary JavaScript in the context of another user's session.
The vulnerability exists due to cross-site scripting in the /s/ajax?action=lead:addLeadTags endpoint when reflecting user-supplied input in the "Tags" input field. A remote attacker can send a specially crafted request to execute arbitrary JavaScript in the context of another user's session.
Affected software
Mautic
How to mitigate CVE-2025-9823
Install security update from vendor's website.
Mautic - addressed in versions 4.4.18, 5.2.8, 6.0.5