The message-page.jsp error page used the value of the HTTP request header X-ProxyContextPath without sanitization, resulting in a reflected XSS attack. Mitigation: The fix to correctly parse and sanitize the request attribute value was applied on the Apache NiFi 1.8.0 release. Users running a prior 1.x release should upgrade to the appropriate release.
Severity
CVSS 3.0
6.1 medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS
2.8% chance of exploitation in the next 30 days; higher than 86% of CVEs (scores of 2026-10-31)