CVE-2025-15055
Published: 09 January 2026
Summary
CVE-2025-15055 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Wordpress (inferred from references). Its CVSS base score is 7.2 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 10.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-15 (Information Output Filtering).
Deeper analysis
CVE-2025-15055 is a stored cross-site scripting (XSS) vulnerability, classified under CWE-79, in the SlimStat Analytics plugin for WordPress. It affects all versions up to and including 5.3.4 due to insufficient input sanitization and output escaping of the 'notes' and 'resource' parameters. This flaw enables the injection of arbitrary web scripts into pages, with a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N).
Unauthenticated attackers can exploit the vulnerability remotely with low complexity and no privileges or user interaction required. By submitting malicious payloads via the vulnerable parameters, they inject scripts that persist and execute in the context of an administrator's browser whenever the Recent Custom Events report is accessed, potentially leading to session hijacking, data theft, or further site compromise.
Advisories reference a patch in WordPress plugins trac changeset 3429990 for wp-slimstat, which security practitioners should apply by updating the plugin beyond version 5.3.4. Further details on the vulnerability and remediation are provided in the Wordfence threat intelligence report.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-1785
Vulnerability details
The SlimStat Analytics plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'notes' and 'resource' parameters in all versions up to, and including, 5.3.4 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated…
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attackers to inject arbitrary web scripts in pages that will execute whenever an administrator accesses the Recent Custom Events report.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Stored XSS in public-facing WordPress plugin directly enables remote exploitation of web app (T1190) and arbitrary script execution for browser session hijacking (T1185).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires validation and sanitization of untrusted input such as the 'notes' and 'resource' parameters before storage, blocking the stored XSS payload at its entry point.
Mandates output filtering/escaping of stored data before rendering in the Recent Custom Events report, neutralizing script execution in the administrator's browser.
Requires timely remediation of identified flaws by applying the available plugin update beyond version 5.3.4, eliminating the root cause of insufficient sanitization and escaping.