CVE-2026-55471

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.6%, top 55% 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
Elevated
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 9.1Exploit: Elevated riskExposed services: Not assessed

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
9.1CRITICALmedium confidence
EG Risk
72
EG Risk 72/100

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%
EPSS PROB
0.6%
EPSS %ILE
45th
KEV
Not listed

Published

June 17, 2026

Last Modified

July 16, 2026

Advisory Details (3)

Auto-updated Sep 16, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
githubMentions a patch (unverified)🟡 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 / EcosystemFix (by version range) / 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 rangeFix by version rangeDependents
ca.uhn.hapi.fhir:org.hl7.fhir.utilities0.0.1 ... 6.9.9 (391 versions)
  • every version up to 6.9.10: fixed in 6.9.10
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 31× 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 171 total refreshes for this CVE.

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

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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 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 0.6% probability of exploitation in the next 30 days (45th percentile of EPSS-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?
A fix for CVE-2026-55471 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-55471 are linked in the Vendor Advisories panel on this page.

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