CVE-2026-85227

CVE-2026-85227 is a medium-severity vulnerability in Misp-project Misp with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

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.

Frequently asked questions

What is CVE-2026-85227?
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.
How severe is CVE-2026-85227?
CVE-2026-85227 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-85227 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-85227?
CVE-2026-85227 affects Misp-project Misp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-85227?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-85227 published?
CVE-2026-85227 was published on 2026-09-03 and last updated on 2026-09-10.

References

Affected products (1)

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