{"id":"CVE-2026-81875","aliases":["EUVD-2026-80993","GHSA-3w98-rrpr-fprr","ROOT-APP-MAVEN-CVE-2026-81875"],"status":"published","title":"HAPI FHIR: SHCParser unbounded DEFLATE decompression causes denial of service","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 consume attacker-controlled Smart Health Card JWT content whose header contains zip: \"DEF\" and whose small raw-DEFLATE payload expands to a very large value. SHCParser.decodeJWT() passes the decoded payload to SHCParser.inflate(), which accumulates all decompressed bytes in a ByteArrayOutputStream without an output-size limit before JSON parsing, and SHCParser.decompress() contains the same unbounded pattern. An application or validator service that accepts attacker-supplied SHC content can therefore suffer excessive heap allocation, severe garbage-collection pressure, request failure, process instability, or process termination. This issue is fixed in version 6.9.12.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0063,"percentile":0.50633,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-20","CWE-400","CWE-409"],"published":"2026-09-16T18:44:47Z","modified":"2026-10-28T11:12:29Z","fixes":[{"ecosystem":"Maven","package":"ca.uhn.hapi.fhir:org.hl7.fhir.r5","fixed_in":["6.9.12"],"sources":["ghsa","osv"]},{"ecosystem":"Maven","package":"ca.uhn.hapi.fhir:org.hl7.fhir.validation","fixed_in":["6.9.12"],"sources":["ghsa","osv"]},{"ecosystem":"Root:Maven","package":"ca.uhn.hapi.fhir:org.hl7.fhir.r5","fixed_in":["6.9.10-aikido.1","6.7.9-aikido.10","6.9.4.1-aikido.3","6.9.0-aikido.11"],"sources":["osv"]},{"ecosystem":"Root:Maven","package":"ca.uhn.hapi.fhir:org.hl7.fhir.validation","fixed_in":["6.9.10-aikido.1","6.7.9-aikido.10","6.9.4.1-aikido.3","6.9.0-aikido.11"],"sources":["osv"]},{"ecosystem":"Root:Maven","package":"io.root.ca.uhn.hapi.fhir:org.hl7.fhir.r5","fixed_in":["6.9.10-root.io.1","6.7.9-root.io.10","6.9.4.1-root.io.3","6.9.0-root.io.11"],"sources":["osv"]},{"ecosystem":"Root:Maven","package":"io.root.ca.uhn.hapi.fhir:org.hl7.fhir.validation","fixed_in":["6.9.10-root.io.1","6.7.9-root.io.10","6.9.4.1-root.io.3","6.9.0-root.io.11"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"Maven","package":"ca.uhn.hapi.fhir:org.hl7.fhir.r5","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.9.11"},{"fixed":"6.9.12"}]}]},{"source":"ghsa","ecosystem":"Maven","package":"ca.uhn.hapi.fhir:org.hl7.fhir.validation","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.9.11"},{"fixed":"6.9.12"}]}]},{"source":"ghsa","ecosystem":"Maven","package":"ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"5.0.0"}]}]},{"source":"osv","ecosystem":"Maven","package":"ca.uhn.hapi.fhir:org.hl7.fhir.r5","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.9.12"}]}],"versions":["0.0.1","0.0.14","0.0.2","0.1.18","1.0.0","1.1.67","4.0.0","4.0.1","4.0.2","4.0.3","4.1.0","4.2.0","5.0.0","5.0.10","5.0.11","5.0.12","5.0.13","5.0.14","5.0.15","5.0.16","5.0.17","5.0.18","5.0.19","5.0.20","5.0.21","5.0.22","5.0.7","5.0.8","5.0.9","5.1.0","5.1.1","5.1.10","5.1.11","5.1.12","5.1.13","5.1.14","5.1.15","5.1.16","5.1.17","5.1.18","5.1.19","5.1.2","5.1.20","5.1.21","5.1.22","5.1.3","5.1.4","5.1.5","5.1.6","5.1.7","5.1.8","5.1.9","5.2.0","5.2.1","5.2.10","5.2.11","5.2.12","5.2.13","5.2.16","5.2.18","5.2.19","5.2.20","5.2.3","5.2.4","5.2.5","5.2.7","5.2.8","5.2.9","5.3.0","5.3.1","5.3.10","5.3.11","5.3.12","5.3.14","5.3.2","5.3.3","5.3.4","5.3.5","5.3.6","5.3.7","5.3.8","5.3.9","5.4.0","5.4.1","5.4.10","5.4.11","5.4.12","5.4.2","5.4.3","5.4.4","5.4.5","5.4.6","5.4.7","5.4.8","5.4.9","5.5.1","5.5.10","5.5.11","5.5.12","5.5.13","5.5.14","5.5.15","5.5.16","5.5.2","5.5.3","5.5.4","5.5.6","5.5.7","5.5.8","5.5.9","5.6.0","5.6.1","5.6.100","5.6.101","5.6.102","5.6.103","5.6.104","5.6.105","5.6.106","5.6.107","5.6.108","5.6.109","5.6.110","5.6.111","5.6.112","5.6.113","5.6.114","5.6.115","5.6.116","5.6.117","5.6.12","5.6.13","5.6.15","5.6.17","5.6.18","5.6.19","5.6.2","5.6.20","5.6.21","5.6.22","5.6.23","5.6.24","5.6.25","5.6.26","5.6.27","5.6.28","5.6.29","5.6.3","5.6.30","5.6.31","5.6.32","5.6.33","5.6.34","5.6.35","5.6.36","5.6.37","5.6.38","5.6.39","5.6.4","5.6.40","5.6.41","5.6.42","5.6.43","5.6.44","5.6.45","5.6.46","5.6.47","5.6.48","5.6.5","5.6.50","5.6.51","5.6.52","5.6.53","5.6.54","5.6.55","5.6.56","5.6.57","5.6.58","5.6.59","5.6.6","5.6.60","5.6.61","5.6.62","5.6.63","5.6.64","5.6.65","5.6.66","5.6.67","5.6.68","5.6.69","5.6.7","5.6.70","5.6.71","5.6.72","5.6.73","5.6.74","5.6.75","5.6.76","5.6.77","5.6.78","5.6.79","5.6.80","5.6.81","5.6.82","5.6.83","5.6.84","5.6.85","5.6.86","5.6.87","5.6.88","5.6.881","5.6.89","5.6.9","5.6.90","5.6.91","5.6.92","5.6.93","5.6.94","5.6.95","5.6.96","5.6.97","5.6.971","5.6.98","5.6.99","6.0.0","6.0.1","6.0.10","6.0.11","6.0.12","6.0.13","6.0.14","6.0.15","6.0.16","6.0.17","6.0.18","6.0.19","6.0.2","6.0.20","6.0.21","6.0.22","6.0.22.1","6.0.22.2","6.0.23","6.0.24","6.0.25","6.0.3","6.0.4","6.0.5","6.0.6","6.0.7","6.0.8","6.0.9","6.1.0","6.1.1","6.1.10","6.1.11","6.1.12","6.1.13","6.1.14","6.1.15","6.1.16","6.1.2","6.1.2.1","6.1.2.2","6.1.3","6.1.4","6.1.5","6.1.6","6.1.7","6.1.8","6.1.9","6.2.0","6.2.1","6.2.10","6.2.11","6.2.12","6.2.13","6.2.14","6.2.15","6.2.2","6.2.3","6.2.4","6.2.5","6.2.6","6.2.6.1","6.2.7","6.2.8","6.2.9","6.3.0","6.3.1","6.3.10","6.3.11","6.3.12","6.3.13","6.3.14","6.3.15","6.3.16","6.3.17","6.3.18","6.3.19","6.3.2","6.3.20","6.3.21","6.3.22","6.3.23","6.3.24","6.3.25","6.3.26","6.3.27","6.3.28","6.3.29","6.3.3","6.3.30","6.3.31","6.3.32","6.3.4","6.3.5","6.3.6","6.3.7","6.3.8","6.3.9","6.4.0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FHIR: SHCParser unbounded DEFLATE decompression causes denial of service","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 consume attacker-controlled Smart Health Card JWT content whose header contains zip: \"DEF\" and whose small raw-DEFLATE payload expands to a very large value. SHCParser.decodeJWT() passes the decoded payload to SHCParser.inflate(), which accumulates all decompressed bytes in a ByteArrayOutputStream without an output-size limit before JSON parsing, and SHCParser.decompress() contains the same unbounded pattern. An application or validator service that accepts attacker-supplied SHC content can therefore suffer excessive heap allocation, severe garbage-collection pressure, request failure, process instability, or process termination. This issue is fixed in version 6.9.12.","status":"published","published":"2026-09-16T18:44:47.591Z","modified":"2026-09-17T16:14:31.374Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-20","CWE-400","CWE-409"],"updated_at":"2026-11-02T13:36:18.075535Z"}],"euvd":[{"id":"EUVD-2026-80993","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 consume attacker-controlled Smart Health Card JWT content whose header contains zip: \"DEF\" and whose small raw-DEFLATE payload expands to a very large value. SHCParser.decodeJWT() passes the decoded payload to SHCParser.inflate(), which accumulates all decompressed bytes in a ByteArrayOutputStream without an output-size limit before JSON parsing, and SHCParser.decompress() contains the same unbounded pattern. An application or validator service that accepts attacker-supplied SHC content can therefore suffer excessive heap allocation, severe garbage-collection pressure, request failure, process instability, or process termination. This issue is fixed in version 6.9.12.","status":"published","published":"2026-09-16T18:44:47Z","modified":"2026-09-17T16:14:31Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T17:28:11.273554Z"}],"ghsa":[{"id":"GHSA-3w98-rrpr-fprr","title":"HAPI FHIR: SHCParser unbounded DEFLATE decompression causes denial of service","description":"### Summary\n`SHCParser` inflates compressed Smart Health Card JWT payloads into memory without a decompressed-size limit. An attacker who can submit SHC content for validation can craft a small compressed JWT payload that expands to a very large byte array, causing memory exhaustion or severe garbage collection pressure.\n\n### Details\nThe vulnerable code is in `org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/elementmodel/SHCParser.java`.\n\n`decodeJWT()` checks `MAX_ALLOWED_SHC_LENGTH`, but this only logs an error and parsing continues:\n\n```java\n// SHCParser.java:282-284\nif (jwt.length() \u003e MAX_ALLOWED_SHC_LENGTH) {\n  logError(...);\n}\n```\n\nIf the header contains `\"zip\":\"DEF\"`, the payload is inflated before JSON parsing:\n\n```java\n// SHCParser.java:300-304\nif (\"DEF\".equals(res.header.asString(\"zip\"))) {\n  payloadJson = inflate(payloadJson);\n}\nres.payload = JsonParser.parseObject(FileUtilities.bytesToString(payloadJson), true);\n```\n\n`inflate()` accumulates all decompressed output in a `ByteArrayOutputStream` and has no maximum output size:\n\n```java\n// SHCParser.java:455-468\nwhile (!inflater.finished()) {\n  final int count = inflater.inflate(buffer);\n  outputStream.write(buffer, 0, count);\n}\nreturn outputStream.toByteArray();\n```\n\nThe same unbounded decompression pattern exists in `decompress()` at `SHCParser.java:410-423`.\n\n### PoC\nCreate a highly compressible SHC-shaped JSON payload, compress it with raw DEFLATE (`new Deflater(9, true)`), Base64URL-encode it as the JWT payload, and set the JWT header to `{\"zip\":\"DEF\"}`.\n\nLocal verification measured the following expansion through `SHCParser.inflate()`:\n\n```text\nplain=1000066 compressed=1052 inflated=1000066 ratio=950\nplain=16000066 compressed=15626 inflated=16000066 ratio=1023\n```\n\nA small compressed payload can therefore allocate many megabytes of heap. Larger payloads can trigger `OutOfMemoryError` or process instability.\n\n### Impact\nThis is a denial-of-service vulnerability. Any validator service or application that accepts attacker-supplied SHC content can be forced to allocate excessive heap memory. Impact ranges from request failure and severe GC pressure to process termination.\n\n### Credits\n- Thai Son Dinh from VinSOC Labs (R\u0026D)","status":"published","published":"2026-09-17T20:32:16Z","modified":"2026-09-17T20:32:20Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-20","CWE-400","CWE-409"],"updated_at":"2026-11-02T14:41:18.357514Z"}],"nvd":[{"id":"CVE-2026-81875","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 consume attacker-controlled Smart Health Card JWT content whose header contains zip: \"DEF\" and whose small raw-DEFLATE payload expands to a very large value. SHCParser.decodeJWT() passes the decoded payload to SHCParser.inflate(), which accumulates all decompressed bytes in a ByteArrayOutputStream without an output-size limit before JSON parsing, and SHCParser.decompress() contains the same unbounded pattern. An application or validator service that accepts attacker-supplied SHC content can therefore suffer excessive heap allocation, severe garbage-collection pressure, request failure, process instability, or process termination. This issue is fixed in version 6.9.12.","status":"published","published":"2026-09-16T19:17:44.25Z","modified":"2026-09-30T17:43:24.057Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-20","CWE-400","CWE-409"],"updated_at":"2026-11-02T14:12:48.630594Z"}],"osv":[{"id":"CVE-2026-81875","title":"HAPI FHIR: SHCParser unbounded DEFLATE decompression causes denial of service","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 consume attacker-controlled Smart Health Card JWT content whose header contains zip: \"DEF\" and whose small raw-DEFLATE payload expands to a very large value. SHCParser.decodeJWT() passes the decoded payload to SHCParser.inflate(), which accumulates all decompressed bytes in a ByteArrayOutputStream without an output-size limit before JSON parsing, and SHCParser.decompress() contains the same unbounded pattern. An application or validator service that accepts attacker-supplied SHC content can therefore suffer excessive heap allocation, severe garbage-collection pressure, request failure, process instability, or process termination. This issue is fixed in version 6.9.12.","status":"published","published":"2026-09-16T18:44:47.591Z","modified":"2026-10-28T11:12:29.303246368Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-20","CWE-400","CWE-409"],"updated_at":"2026-11-02T15:45:18.131258Z"},{"id":"GHSA-3w98-rrpr-fprr","title":"HAPI FHIR: SHCParser unbounded DEFLATE decompression causes denial of service","description":"### Summary\n`SHCParser` inflates compressed Smart Health Card JWT payloads into memory without a decompressed-size limit. An attacker who can submit SHC content for validation can craft a small compressed JWT payload that expands to a very large byte array, causing memory exhaustion or severe garbage collection pressure.\n\n### Details\nThe vulnerable code is in `org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/elementmodel/SHCParser.java`.\n\n`decodeJWT()` checks `MAX_ALLOWED_SHC_LENGTH`, but this only logs an error and parsing continues:\n\n```java\n// SHCParser.java:282-284\nif (jwt.length() \u003e MAX_ALLOWED_SHC_LENGTH) {\n  logError(...);\n}\n```\n\nIf the header contains `\"zip\":\"DEF\"`, the payload is inflated before JSON parsing:\n\n```java\n// SHCParser.java:300-304\nif (\"DEF\".equals(res.header.asString(\"zip\"))) {\n  payloadJson = inflate(payloadJson);\n}\nres.payload = JsonParser.parseObject(FileUtilities.bytesToString(payloadJson), true);\n```\n\n`inflate()` accumulates all decompressed output in a `ByteArrayOutputStream` and has no maximum output size:\n\n```java\n// SHCParser.java:455-468\nwhile (!inflater.finished()) {\n  final int count = inflater.inflate(buffer);\n  outputStream.write(buffer, 0, count);\n}\nreturn outputStream.toByteArray();\n```\n\nThe same unbounded decompression pattern exists in `decompress()` at `SHCParser.java:410-423`.\n\n### PoC\nCreate a highly compressible SHC-shaped JSON payload, compress it with raw DEFLATE (`new Deflater(9, true)`), Base64URL-encode it as the JWT payload, and set the JWT header to `{\"zip\":\"DEF\"}`.\n\nLocal verification measured the following expansion through `SHCParser.inflate()`:\n\n```text\nplain=1000066 compressed=1052 inflated=1000066 ratio=950\nplain=16000066 compressed=15626 inflated=16000066 ratio=1023\n```\n\nA small compressed payload can therefore allocate many megabytes of heap. Larger payloads can trigger `OutOfMemoryError` or process instability.\n\n### Impact\nThis is a denial-of-service vulnerability. Any validator service or application that accepts attacker-supplied SHC content can be forced to allocate excessive heap memory. Impact ranges from request failure and severe GC pressure to process termination.\n\n### Credits\n- Thai Son Dinh from VinSOC Labs (R\u0026D)","status":"published","published":"2026-09-17T20:32:16Z","modified":"2026-09-17T20:45:05.295312533Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-20","CWE-400","CWE-409"],"updated_at":"2026-11-02T15:46:36.092962Z"},{"id":"ROOT-APP-MAVEN-CVE-2026-81875","title":"CVE-2026-81875 in ca.uhn.hapi.fhir:org.hl7.fhir.r5 - Patched by Root","description":"Root has patched CVE-2026-81875 in the ca.uhn.hapi.fhir:org.hl7.fhir.r5 package for Root:Maven. Multiple fixed versions available.","status":"published","published":"2026-09-28T09:36:54Z","modified":"2026-09-28T10:15:04.54194532Z","updated_at":"2026-11-02T15:53:27.066589Z"}]}}