Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
The Maven package ca.uhn.hapi.fhir:org.hl7.fhir.dstu2 (and the related org.hl7.fhir.convertors, org.hl7.fhir.validation, and org.hl7.fhir.validation.cli modules) is vulnerable in versions before 6.9.10. The DSTU2 FHIRPathEngine matches() function lacks regex timeout protection, so a user-supplied FHIRPath expression with a catastrophically backtracking regular expression can exhaust CPU. No authentication is required. Upgrade to version 6.9.10, where the fix is listed.
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 |
|---|---|---|---|---|
| 7.5 | High | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0068, the 52nd percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:20 UTC First seen by agentprime
- 31 Oct 2026, 14:20 UTC Confirmed by OSV