CVE-2026-55471

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 69% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 3 sources updated this weekElevated
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: Elevated riskExposed: 0

A fix is available — apply it.

HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.10, org.hl7.fhir.utilities.XsltUtilities saxonTransform(...) overloads instantiated a bare net.sf.saxon.TransformerFactoryImpl() without ACCESS_EXTERNAL_DTD or ACCESS_EXTERNAL_STYLESHEET restrictions, allowing an attacker who controls or can tamper with transformed XML to trigger XML External Entity injection for local file disclosure and blind XXE or SSRF to arbitrary URLs reachable from the host. This issue is fixed in version 6.9.10.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
72(Attend)
EG Risk 72/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity91% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
31%
KEV
Not listed

Published

June 17, 2026

Last Modified

July 16, 2026

Advisory Details (3)

Auto-updated Aug 1, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available

XXE in XsltUtilities.saxonTransform via unhardened Saxon TransformerFactory · Advisory · hapifhir/org.hl7.fhir.core · GitHub

https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2f55-g35j-5jmf
github_release Patch Available

6.9.10

Patch available: hapifhir/org.hl7.fhir.core 6.9.10

https://github.com/hapifhir/org.hl7.fhir.core/releases/tag/6.9.10
github_commit Patch Available

commit 01ca2ecdefec (hapifhir/org.hl7.fhir.core)

Patch available: hapifhir/org.hl7.fhir.core 6.9.10 (contains commit 01ca2ecdefec)

https://github.com/hapifhir/org.hl7.fhir.core/commit/01ca2ecdefec9b33204d2495fe78af8c0dc52298

Vendor Advisories for CVE-2026-55471(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatorg.hl7.fhir.utilities2026-08-13redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
Maven(1)
PackageVulnerable rangeFixed inDependents
ca.uhn.hapi.fhir:org.hl7.fhir.utilities0.0.1 ... 6.9.9 (391 versions)6.9.10—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 41× in last 7d / 82× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 106 total refreshes for this CVE.

  1. 2026-08-21 05:25 UTCVendor advisory
  2. 2026-08-20 23:55 UTCEG score recompute
  3. 2026-08-20 23:55 UTCVendor advisory
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-20 20:08 UTCVendor advisory
  6. 2026-08-20 16:15 UTCVendor advisory
  7. 2026-08-20 12:26 UTCVendor advisory
  8. 2026-08-20 08:12 UTCEG score recompute
  9. 2026-08-20 08:12 UTCVendor advisory
  10. 2026-08-19 17:04 UTCEPSS rescore
  11. 2026-08-19 12:44 UTCVendor advisory
  12. 2026-08-19 08:08 UTCEG score recompute
  13. 2026-08-19 08:08 UTCVendor advisory
  14. 2026-08-18 13:48 UTCEPSS rescore
  15. 2026-08-17 13:47 UTCEPSS rescore
  16. 2026-08-17 12:29 UTCVendor advisory
  17. 2026-08-17 08:13 UTCVendor advisory
  18. 2026-08-17 04:26 UTCVendor advisory
  19. 2026-08-17 00:39 UTCVendor advisory
  20. 2026-08-16 20:52 UTCVendor advisory
  21. 2026-08-16 16:21 UTCEG score recompute
  22. 2026-08-16 16:21 UTCVendor advisory
  23. 2026-08-16 14:56 UTCEPSS rescore
  24. 2026-08-16 12:33 UTCVendor advisory
  25. 2026-08-16 08:45 UTCVendor advisory
Show 75 more
  1. 2026-08-16 04:58 UTCEG score recompute
  2. 2026-08-16 04:58 UTCVendor advisory
  3. 2026-08-16 02:14 UTCEPSS rescore
  4. 2026-08-16 01:11 UTCVendor advisory
  5. 2026-08-15 21:24 UTCVendor advisory
  6. 2026-08-15 16:55 UTCVendor advisory
  7. 2026-08-15 13:08 UTCVendor advisory
  8. 2026-08-15 09:10 UTCVendor advisory
  9. 2026-08-15 05:15 UTCEG score recompute
  10. 2026-08-15 05:15 UTCVendor advisory
  11. 2026-08-15 01:30 UTCEPSS rescore
  12. 2026-08-15 01:27 UTCVendor advisory
  13. 2026-08-14 21:40 UTCVendor advisory
  14. 2026-08-14 17:53 UTCVendor advisory
  15. 2026-08-14 14:01 UTCVendor advisory
  16. 2026-08-14 10:14 UTCVendor advisory
  17. 2026-08-14 06:27 UTCVendor advisory
  18. 2026-08-14 02:39 UTCVendor advisory
  19. 2026-08-13 22:52 UTCEG score recompute
  20. 2026-08-13 22:00 UTCEPSS rescore
  21. 2026-08-12 15:04 UTCEG score recompute
  22. 2026-08-12 13:51 UTCEPSS rescore
  23. 2026-08-11 16:19 UTCEG score recompute
  24. 2026-08-11 01:06 UTCEG score recompute
  25. 2026-08-11 00:00 UTCEPSS rescore
  26. 2026-08-09 16:55 UTCEG score recompute
  27. 2026-08-09 13:46 UTCEPSS rescore
  28. 2026-08-08 18:13 UTCEG score recompute
  29. 2026-08-08 16:37 UTCEPSS rescore
  30. 2026-08-07 19:29 UTCEG score recompute
  31. 2026-08-06 16:56 UTCEG score recompute
  32. 2026-08-06 13:47 UTCEPSS rescore
  33. 2026-08-05 21:59 UTCEG score recompute
  34. 2026-08-05 19:17 UTCEPSS rescore
  35. 2026-08-04 15:25 UTCEG score recompute
  36. 2026-08-04 15:10 UTCEPSS rescore
  37. 2026-08-04 10:39 UTCEPSS rescore
  38. 2026-08-03 14:25 UTCEG score recompute
  39. 2026-08-03 10:36 UTCEPSS rescore
  40. 2026-08-02 04:04 UTCEG score recompute
  41. 2026-08-02 02:27 UTCEPSS rescore
  42. 2026-08-01 05:20 UTCEG score recompute
  43. 2026-08-01 04:16 UTCEPSS rescore
  44. 2026-07-30 22:35 UTCEG score recompute
  45. 2026-07-30 16:28 UTCEPSS rescore
  46. 2026-07-30 03:18 UTCEG score recompute
  47. 2026-07-30 01:30 UTCEPSS rescore
  48. 2026-07-29 02:04 UTCEG score recompute
  49. 2026-07-28 15:37 UTCEPSS rescore
  50. 2026-07-27 18:08 UTCEG score recompute
  51. 2026-07-26 19:01 UTCEG score recompute
  52. 2026-07-26 14:54 UTCEPSS rescore
  53. 2026-07-25 14:18 UTCEPSS rescore
  54. 2026-07-24 14:18 UTCEPSS rescore
  55. 2026-07-23 14:18 UTCEPSS rescore
  56. 2026-07-23 03:20 UTCEG score recompute
  57. 2026-07-22 14:08 UTCEPSS rescore
  58. 2026-07-21 15:25 UTCEPSS rescore
  59. 2026-07-20 17:08 UTCEPSS rescore
  60. 2026-07-19 14:31 UTCEPSS rescore
  61. 2026-07-19 14:31 UTCEPSS rescore
  62. 2026-07-19 02:29 UTCEPSS rescore
  63. 2026-07-18 10:04 UTCEPSS rescore
  64. 2026-07-16 21:23 UTCEG score recompute▲ 0.40
  65. 2026-07-16 17:05 UTCNVD updateCVSS v3 → 9.1 · severity → CRITICAL
  66. 2026-07-16 17:03 UTCEPSS rescore
  67. 2026-07-15 16:57 UTCEPSS rescore
  68. 2026-07-15 16:57 UTCEPSS rescore
  69. 2026-07-15 02:00 UTCEPSS rescore
  70. 2026-07-15 02:00 UTCEPSS rescore
  71. 2026-07-13 22:31 UTCEPSS rescore
  72. 2026-07-13 06:13 UTCEPSS rescore
  73. 2026-07-13 06:13 UTCEPSS rescore
  74. 2026-07-12 05:46 UTCEPSS rescore
  75. 2026-07-11 08:27 UTCEPSS rescore

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Frequently asked(5)

What is CVE-2026-55471?
CVE-2026-55471 is a critical vulnerability published on June 17, 2026. HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.10, org.hl7.fhir.utilities.XsltUtilities saxonTransform(...) overloads instantiated a bare net.sf.saxon.TransformerFactoryImpl() without ACCESSEXTERNALDTD or…
When was CVE-2026-55471 disclosed?
CVE-2026-55471 was first published in the National Vulnerability Database on June 17, 2026, with the most recent update on July 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55471 actively exploited?
CVE-2026-55471 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 69.0% of all scored CVEs.
What is the CVSS score of CVE-2026-55471?
CVE-2026-55471 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-55471?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55471, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-55471

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