CVE-2026-55471

Description

A flaw was found in the HAPI FHIR XsltUtilities component. The saxonTransform functions within this utility do not adequately restrict external entity access when processing XML. This oversight allows an attacker, who can control or tamper with the XML data being transformed, to inject malicious XML External Entities (XXE). Successful exploitation can lead to local file disclosure, enabling the attacker to read sensitive files from the system. Additionally, it can result in Server-Side Request Forgery (SSRF), where the attacker can force the system to make requests to arbitrary network resources, potentially exposing internal network information or cloud metadata.

Statement

This is an Important flaw in HAPI FHIR XsltUtilities that allows XML External Entity (XXE) injection. An unauthenticated, remote attacker can exploit this by providing specially crafted XML data to disclose local files or perform Server-Side Request Forgery (SSRF). This is critical in environments where Red Hat products, such as Enterprise Application Platform or Red Hat build of Apache Camel, process untrusted XML input.

Mitigation

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score7.59.1N/A
Attack VectorNetworkNetworkN/A
Attack ComplexityLowLowN/A
Privileges RequiredNoneNoneN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityHighHighN/A
Integrity ImpactNoneHighN/A
Availability ImpactNoneNoneN/A

Vector

Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Understanding the Weakness (CWE)

CWE-611

Confidentiality

Technical Impact: Read Application Data; Read Files or Directories

If the attacker is able to include a crafted DTD and a default entity resolver is enabled, the attacker may be able to access arbitrary files on the system. By submitting an XML file that defines an external entity with a file:// URI, an attacker can cause the processing application to read the contents of a local file. For example, a URI such as "file:///c:/winnt/win.ini" designates (in Windows) the file C:\Winnt\win.ini, or file:///etc/passwd designates the password file in Unix-based systems. Once the content of the URI is read, it is fed back into the application that is processing the XML. This application may echo back the data (e.g., in an error message), thereby exposing the file contents.

Integrity

Technical Impact: Bypass Protection Mechanism

An attacker may supply a crafted DTD using URIs with schemes such as http://, forcing the application to make outgoing HTTP requests to servers that the attacker cannot reach directly, which can be used to bypass firewall restrictions; hide the source of attacks such as port scanning; or otherwise leverage the server's trust relationship with other entities.

Availability

Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)

The product could consume excessive CPU cycles or memory using a URI that points to a large file, or a device that always returns data such as /dev/random. Alternately, the URI could reference a file that contains many nested or recursive entity references to further slow down parsing.

Frequently Asked Questions

Not sure what something means? Check out our Security Glossary.

Want to get errata notifications? Sign up here.