CVE-2026-34359Public exploitNetwork attack vector

Credential theft via boundaryless URL prefix matching

Published Mar 31, 2026 · Updated Mar 31, 2026

Credential leakage in HAPI FHIR org.hl7.fhir.core before 6.9.4 allows remote attackers to obtain server credentials via HTTP redirects. ManagedWebAccessUtils.getServer() uses String.startsWith() without a host-boundary check, so a lookalike redirect URL inherits Bearer, Basic, API-key, or custom authentication headers. Exploitation requires authenticated server details plus attacker control of a redirect path, such as through a man-in-the-middle position, and exposes credentials usable against the legitimate server.

CVSS severity7.4
High
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Credential leakage in HAPI FHIR org.hl7.fhir.core before 6.9.4 allows remote attackers to obtain server credentials via HTTP redirects. ManagedWebAccessUtils.getServer() uses String.startsWith() without a host-boundary check, so a lookalike redirect URL inherits Bearer, Basic, API-key, or custom authentication headers. Exploitation requires authenticated server details plus attacker control of a redirect path, such as through a man-in-the-middle position, and exposes credentials usable against the legitimate server.

The record

CVE
CVE-2026-34359
Published
Mar 31, 2026
Updated
Mar 31, 2026
Vendor
HAPI FHIR
Product
org.hl7.fhir.core
Classifications
CWE-346, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 31, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 31, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 6.9.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

HAPI FHIR · org.hl7.fhir.coreversion=< 6.9.4

Published CVSS scores

9.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
7.4GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-346Origin Validation Error
T1557Adversary-in-the-Middle

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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