{"cve":"CVE-2026-103388","nvd":{"published":"2026-09-30T15:22:27.143","modified":"2026-09-30T16:17:08.983","status":"Deferred","description":"MISP renders the source field of a Galaxy Cluster as a clickable hyperlink whenever the stored value passes PHP's FILTER_VALIDATE_URL validation. Because FILTER_VALIDATE_URL accepts the javascript: URI scheme, a user with galaxy editor privileges on the local instance or on a synced instance could store a javascript: URL as the cluster source.\n\nWhen another user views the affected Galaxy Cluster and clicks the rendered link, the embedded script executes in the victim's browser context, enabling session hijacking, data exfiltration, or actions performed on behalf of the victim.\n\nPreconditions:\n\n- Attacker must hold galaxy editor privileges (local or via sync).\n\n- Victim must view the affected cluster and click the malicious link.\n\nImpact:\n\n- Stored cross-site scripting (XSS) in the victim's browser.\n\n- Potential session theft, credential harvesting, or unauthorized actions within the MISP application.\n\nAffected: <2.5.48.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","score":6.2},"cvss_v3":null,"cwes":["CWE-79"],"references":["https://github.com/MISP/MISP/commit/118528767"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:48.555445741+00:00"},"epss":{"cve":"CVE-2026-103388","score":0.00243,"percentile":0.15366,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}