CVE-2026-85227
Reflected Cross-Site Scripting in MISP Event Filtering via taggedAttributes and galaxyAttachedAttributes Parameters
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Active
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.1
Reflected Cross-Site Scripting in MISP Event Filtering via taggedAttributes and galaxyAttachedAttributes Parameters
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.
- Record
CVE-2026-85227- CVSS 4.0
- 6.1 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:H - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2026-70500
6.1
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.
- Record
EUVD-2026-70500- CVSS 4.0
- 6.1 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-mj6h-p8f5-39rh
6.1
MISP contains a reflected Cross-Site Scripting (XSS) vulnerability in the event attribute...
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.
- Record
GHSA-mj6h-p8f5-39rh- CVSS 4.0
- 6.1 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
6.1
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.
- Record
CVE-2026-85227- CVSS 4.0
- 6.1 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
6.1
Reflected Cross-Site Scripting in MISP Event Filtering via taggedAttributes and galaxyAttachedAttributes Parameters
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.
- Record
CVE-2026-85227- CVSS 4.0
- 6.1 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:H - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-85227 is a medium vulnerability (CVSS 6.1) in Misp, published September 3, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 16th percentile. No source names a fixed version.