What’s Vulnerable › Vulnerabilities
CVE-2026-85227: Reflected Cross-Site Scripting in MISP Event Filtering via taggedAttributes and galaxyAttachedAttributes Parameters
- Severity: medium (CVSS 6.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-09-03 · updated 2026-09-10
- Weakness: CWE-79
Description
MISP contains a reflected Cross-Site Scripting (XSS) vulnerability in the event attribute filtering query builder. The taggedAttributes and galaxyAttachedAttributes URL parameters were inserted into the query-builder rules without HTML escaping before being serialized as JSON and embedded inside a <script> element. Because JsonTool::encode() uses JSON_UNESCAPED_SLASHES, an attacker-controlled value containing a closing </script> sequence could terminate the surrounding script element and inject arbitrary HTML or JavaScript. For example, a specially crafted viewEventAttributes URL could contain malicious content in one of the affected filter parameters. An attacker could exploit the vulnerability by convincing an authenticated MISP user to follow a crafted URL. Successful exploitation would execute attacker-controlled JavaScript in the security context of the MISP instance and with the privileges of the victim's authenticated browser session. This could allow access to information available to the victim, modification of data through authenticated requests, or other actions permitted by the victim's MISP permissions. The vulnerability is addressed by applying HTML escaping with h() to both scalar and array values before they are inserted into the DOM.
Affected products
- MISP: before 2.5.46 — fixed in 2.5.46
How to fix
Upgrade to a fixed version: MISP 2.5.46. Check the vendor advisory for mitigations.
References
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