A malicious host header in an incoming HTTP request could cause NiFi to load resources from an external server. The fix to sanitize host headers and compare to a controlled whitelist was applied on the Apache NiFi 1.5.0 release. Users running a prior 1.x release should upgrade to the appropriate release.
Severity
CVSS 3.0
7.5 high
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS
2.8% chance of exploitation in the next 30 days; higher than 86% of CVEs (scores of 2026-10-31)