Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
HAPI FHIR packages from the ca.uhn.hapi.fhir group, including org.hl7.fhir.r4, org.hl7.fhir.r5 and org.hl7.fhir.validation, are affected in versions before 6.4.0. An attacker who can supply a crafted XML request containing malicious entities may be able to read sensitive information or execute arbitrary code. Upgrade the affected packages to version 6.4.0 or later.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 9.8 | Critical | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | GitHub Advisory Database |
- CISA KEV Not listed.
- EPSS 0.019, the 79th percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 15:13 UTC First seen by agentprime
- 31 Oct 2026, 15:13 UTC Confirmed by OSV