{"id":"CVE-2026-85227","state":"PUBLISHED","title":"Reflected Cross-Site Scripting in MISP Event Filtering via taggedAttributes and galaxyAttachedAttributes Parameters","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.\n\n\nBecause 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.\n\n\nAn 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.\n\n\nThe vulnerability is addressed by applying HTML escaping with h() to both scalar and array values before they are inserted into the DOM.","publishedAt":"2026-09-03T14:42:02.782Z","updatedAt":"2026-09-03T14:57:46.804Z","severity":{"score":6.1,"label":"Medium","version":"4.0","vector":"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","source":"CIRCL"},"assigner":"CIRCL","products":["misp misp"],"affected":[{"vendor":"misp","product":"misp","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.5.45","versionType":"semver"}],"repo":"https://github.com/MISP/MISP/"}],"references":["https://github.com/MISP/MISP/commit/de51a16db"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/85xxx/CVE-2026-85227.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-85227","state":"PUBLISHED","datePublished":"2026-09-03T14:42:02.782Z","dateUpdated":"2026-09-03T14:57:46.804Z","assignerShortName":"CIRCL","assignerOrgId":"5a6e4751-2f3f-4070-9419-94fb35b644e8","dateReserved":"2026-09-03T14:41:58.951Z"},"containers":{"cna":{"title":"Reflected Cross-Site Scripting in MISP Event Filtering via taggedAttributes and galaxyAttachedAttributes Parameters","descriptions":[{"lang":"en","value":"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.\n\n\nBecause 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.\n\n\nAn 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.\n\n\nThe vulnerability is addressed by applying HTML escaping with h() to both scalar and array values before they are inserted into the DOM."}],"affected":[{"vendor":"misp","product":"misp","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.5.45","versionType":"semver"}],"repo":"https://github.com/MISP/MISP/"}],"references":[{"url":"https://github.com/MISP/MISP/commit/de51a16db","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":6.1,"baseSeverity":"MEDIUM","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"ACTIVE","valueDensity":"NOT_DEFINED","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","description":"CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting')","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"CIRCL","orgId":"5a6e4751-2f3f-4070-9419-94fb35b644e8","dateUpdated":"2026-09-03T14:42:02.782Z"},"credits":[{"lang":"en","type":"remediation developer","value":"Andras Iklody"},{"lang":"en","type":"finder","value":"elhoim"}],"impacts":[{"capecId":"CAPEC-63","descriptions":[{"lang":"en","value":"CAPEC-63 Cross-Site Scripting (XSS)"}]}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 0.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-03T14:57:24.443527Z","id":"CVE-2026-85227","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-03T14:57:46.804Z"}}]}}}