Authenticated JavaScript execution via unescaped tag reflection
Published Sep 3, 2025 · Updated Sep 3, 2025
Reflected XSS in affected Mautic releases before 4.4.17, 5.2.8, or 6.0.5 allows remote authenticated users to execute JavaScript. The Tags field at /s/ajax?action=lead:addLeadTags reflects submitted text into the immediate HTTP response without proper output escaping, even though later storage and retrieval are sanitized. Exploitation requires a logged-in attacker and active interaction by another user; successful execution can read session-accessible data or perform actions with that user's privileges.
Summary
What happened
Reflected XSS in affected Mautic releases before 4.4.17, 5.2.8, or 6.0.5 allows remote authenticated users to execute JavaScript. The Tags field at /s/ajax?action=lead:addLeadTags reflects submitted text into the immediate HTTP response without proper output escaping, even though later storage and retrieval are sanitized. Exploitation requires a logged-in attacker and active interaction by another user; successful execution can read session-accessible data or perform actions with that user's privileges.
The record
- CVE
- CVE-2025-9823
- Published
- Sep 3, 2025
- Updated
- Sep 3, 2025
- Vendor
- Acquia
- Product
- Mautic
- Classifications
- CWE-79, CAPEC-591, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 3, 2025CVE publishedPublication date reported by the CVE source.
- Sep 3, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 4.4.0 << 4.4.17
- Affected versionversion=>= 5.0.0-alpha << 5.2.8
- Affected versionversion=>= 6.0.0-alpha << 6.0.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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