{"cve":"CVE-2026-81876","nvd":{"published":"2026-09-16T19:17:44.450","modified":"2026-09-30T17:43:24.057","status":"Awaiting Analysis","description":"HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to version 6.9.12, SHCParser in org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/elementmodel/SHCParser.java can enter an infinite loop while processing attacker-controlled Smart Health Card JWT content whose header contains zip: \"DEF\" and whose raw-DEFLATE payload is empty or truncated. SHCParser.decodeJWT() reaches SHCParser.inflate(), where Inflater.inflate() can return zero while Inflater.finished() remains false and Inflater.needsInput() is true. The loop also lacks an Inflater.needsDictionary() termination check, SHCParser.decompress() contains the same zero-progress pattern, and ResourceChecker.java can reach SHC parsing during file-format detection. A malformed validation request can pin a JVM worker thread indefinitely, and concurrent requests can exhaust all validation workers. This issue is fixed in version 6.9.12.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-20","CWE-400","CWE-835"],"references":["https://github.com/hapifhir/org.hl7.fhir.core/commit/d804558bd77372b1629e55a5b901cad3f5134cdc","https://github.com/hapifhir/org.hl7.fhir.core/commit/edd5d8c139e669e39270785f08be7b63aefef24c","https://github.com/hapifhir/org.hl7.fhir.core/pull/2493","https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-gq9c-wmrm-5hvr","https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-gq9c-wmrm-5hvr"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:54:41.405518556+00:00"},"epss":{"cve":"CVE-2026-81876","score":0.0063,"percentile":0.49891,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-gq9c-wmrm-5hvr","url":"https://osv.dev/vulnerability/GHSA-gq9c-wmrm-5hvr","summary":"HAPI FHIR: SHCParser DEFLATE infinite loop causes denial of service","modified":"2026-09-17T20:45:06.995458659Z","packages":[{"ecosystem":"Maven","name":"ca.uhn.hapi.fhir:org.hl7.fhir.r5","purl":"pkg:maven/ca.uhn.hapi.fhir/org.hl7.fhir.r5","ranges":["<6.9.12"],"fixed":["6.9.12"]},{"ecosystem":"Maven","name":"ca.uhn.hapi.fhir:org.hl7.fhir.validation","purl":"pkg:maven/ca.uhn.hapi.fhir/org.hl7.fhir.validation","ranges":["<6.9.12"],"fixed":["6.9.12"]},{"ecosystem":"Maven","name":"ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli","purl":"pkg:maven/ca.uhn.hapi.fhir/org.hl7.fhir.validation.cli","ranges":["<6.9.12"],"fixed":["6.9.12"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}