Apache NiFi fails to validate proxy host headers when constructing qualified URLs (CVE-2026-54665) | HOL Guard CVE

Medium · CVSS 6.3CVE-2026-54665GHSA-8VM2-C32J-MVFR

Apache NiFi fails to validate proxy host headers when constructing qualified URLs

Answer in brief

CVE-2026-54665 records a Medium severity (CVSS 6.3) vulnerability in Apache NiFi fails to validate proxy host headers when constructing qualified URLs. The current sources do not mark it as known exploited. The current feed maps org.apache.nifi:nifi-jetty (maven), org.apache.nifi:nifi-jetty (maven). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jun 22, 2026Updated Sep 11, 2026Source checked Sep 12, 2026First seen by HOL Jun 22, 2026Material review Sep 11, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.3
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 6.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps org.apache.nifi:nifi-jetty (maven), org.apache.nifi:nifi-jetty (maven). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
org.apache.nifi:nifi-jettymaven	<2.10.0	2.10.0
org.apache.nifi:nifi-jettymaven	>=0 <2.10.0	2.10.0

Recommended response

Check inventory. Check lockfiles and deployed manifests for org.apache.nifi:nifi-jetty, org.apache.nifi:nifi-jetty.
Review the reported fix. Update org.apache.nifi:nifi-jetty to 2.10.0; org.apache.nifi:nifi-jetty to 2.10.0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jun 22, 2026
Evidence: source:ghsa:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:ghsa:source_dates:source-dates:record
First seen by HOL
Jun 22, 2026

Sources and claim methodology

Upstream source description

Apache NiFi 0.0.1 through 2.9.0 support building qualified URLs from one of several HTTP request headers that provide an alternative to the standard Host header without validating the values provided. Apache NiFi 1.6.0 introduced a configurable application property to restrict values provided in the HTTP Host header, but did not apply the validation to alternative Proxy and Forwarded headers. The absence of proxy host header validation allowed a client to instruct Apache NiFi web services to construct invalid qualified URLs for redirection or data references. Upgrading to Apache NiFi 2.10.0 is the recommended mitigation, which implements validation for the X-ProxyHost and X-Forwarded-Host HTTP request headers based on the nifi.web.proxy.host property. Enabling header validation requires configuring the application with HTTPS. Reverse proxy servers in front of Apache NiFi are responsible for filtering input request headers and providing allowed values to the application.

Quoted source text, attributed separately from HOL analysis.