Vulnerability · Published Mar 31, 2026 · Assigned by GitHub_M

CVE-2026-34359HAPI FHIR: Authentication Credential Leakage via Improper URL Prefix Matching on HTTP Redirect in HAPI FHIR Core

High 7.4

In plain English

A high-severity security flaw in org.hl7.fhir.core from hapifhir. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.4High

Exploit odds (30 days)0.2%top 94.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to version 6.9.4, ManagedWebAccessUtils.getServer() uses String.startsWith() to match request URLs against configured server URLs for authentication credential dispatch. Because configured server URLs (e.g., http://tx.fhir.org) lack a trailing slash or host boundary check, an attacker-controlled domain like http://tx.fhir.org.attacker.com matches the prefix and receives Bearer tokens, Basic auth credentials, or API keys when the HTTP client follows a redirect to that domain. This issue has been patched in version 6.9.4.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Maven	ca.uhn.hapi.fhir:org.hl7.fhir.core	6.9.4	GHSA-fgv2-4q4g-wc35
Maven	ca.uhn.hapi.fhir:org.hl7.fhir.utilities	6.9.4	GHSA-fgv2-4q4g-wc35

Affected products (as reported)

Vendor	Product	Versions
hapifhir	org.hl7.fhir.core	< 6.9.4

Weakness: CWE-346 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

References

https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-fgv2-4q4g-wc35 x_refsource_CONFIRM