Infinite loop Affecting ca.uhn.hapi.fhir:org.hl7.fhir.r5 package, versions [,6.9.11)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JAVA-CAUHNHAPIFHIR-19963994
- published20 Sept 2026
- disclosed17 Sept 2026
- creditsondt99
Introduced: 17 Sep 2026
NewCVE-2026-81876 (opens in a new tab)How to fix?
Upgrade ca.uhn.hapi.fhir:org.hl7.fhir.r5 to version 6.9.11 or higher.
Overview
Affected versions of this package are vulnerable to Infinite loop via the inflate process in org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/elementmodel/SHCParser.java. An attacker can pin a JVM worker thread indefinitely by supplying a malformed Smart Health Card JWT with zip:"DEF" and an empty or truncated DEFLATE payload. When SHCParser.inflate() processes that input, it loops on Inflater.finished() without making progress, so validation never returns. Services that accept SHC content for validation or SHC-looking input for file detection can be tied up by a small number of crafted requests.