CVE-2026-81875: CWE-20: Improper Input Validation in hapifhir org.hl7.fhir.core
CVE-2026-81875 is a high-severity vulnerability in HAPI FHIR's SHCParser component prior to version 6.9.12. The vulnerability arises from improper input validation of Smart Health Card JWT content compressed with DEFLATE. The parser decompresses attacker-controlled payloads without limiting output size, leading to excessive memory consumption and potential process instability or termination. This issue is fixed in version 6.9.12.
AI Analysis
Technical Summary
HAPI FHIR versions before 6.9.12 contain an improper input validation vulnerability in the SHCParser class (org.hl7.fhir.r5.elementmodel.SHCParser). When processing Smart Health Card JWTs with a header indicating DEFLATE compression (zip: "DEF"), the parser decompresses the payload into a ByteArrayOutputStream without enforcing any output size limits. This unbounded decompression can cause excessive heap memory allocation, severe garbage collection pressure, and may result in request failures, process instability, or termination. The vulnerability is addressed by limiting decompression output size in version 6.9.12.
Potential Impact
An attacker can supply specially crafted Smart Health Card JWT content that decompresses to a very large size, causing excessive memory usage and potentially crashing or destabilizing applications or validator services that use the vulnerable SHCParser. This results in denial of service conditions but does not impact confidentiality or integrity.
Mitigation Recommendations
Upgrade to HAPI FHIR version 6.9.12 or later, where the SHCParser properly limits decompression output size to prevent excessive memory consumption. No other mitigations are specified. Patch status is confirmed fixed in 6.9.12.
CVE-2026-81875: CWE-20: Improper Input Validation in hapifhir org.hl7.fhir.core
Description
CVE-2026-81875 is a high-severity vulnerability in HAPI FHIR's SHCParser component prior to version 6.9.12. The vulnerability arises from improper input validation of Smart Health Card JWT content compressed with DEFLATE. The parser decompresses attacker-controlled payloads without limiting output size, leading to excessive memory consumption and potential process instability or termination. This issue is fixed in version 6.9.12.
CVSS v3.1
Score 7.5high
Affected software
hapifhir
org.hl7.fhir.core
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
HAPI FHIR versions before 6.9.12 contain an improper input validation vulnerability in the SHCParser class (org.hl7.fhir.r5.elementmodel.SHCParser). When processing Smart Health Card JWTs with a header indicating DEFLATE compression (zip: "DEF"), the parser decompresses the payload into a ByteArrayOutputStream without enforcing any output size limits. This unbounded decompression can cause excessive heap memory allocation, severe garbage collection pressure, and may result in request failures, process instability, or termination. The vulnerability is addressed by limiting decompression output size in version 6.9.12.
Potential Impact
An attacker can supply specially crafted Smart Health Card JWT content that decompresses to a very large size, causing excessive memory usage and potentially crashing or destabilizing applications or validator services that use the vulnerable SHCParser. This results in denial of service conditions but does not impact confidentiality or integrity.
Mitigation Recommendations
Upgrade to HAPI FHIR version 6.9.12 or later, where the SHCParser properly limits decompression output size to prevent excessive memory consumption. No other mitigations are specified. Patch status is confirmed fixed in 6.9.12.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-08-27T17:48:42.121Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aaae7b755bf5e2cf5087554
Added to database: 09/16/2026, 19:02:15 UTC
Last enriched: 09/16/2026, 19:16:36 UTC
Last updated: 09/16/2026, 19:21:37 UTC
Views: 3
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