CVE-2026-55470
HAPI FHIR: DSTU2 FHIRPathEngine.matches() missing RegexTimeout protection allows ReDoS
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.10, the fix for CVE-2026-45367 incompletely patched the DSTU2 module, leaving FHIRPathEngine.matches() in org.hl7.fhir.dstu2/utils/FHIRPathEngine.java to call raw String.matches(sw) without RegexTimeout protection while replaceMatches() was updated, allowing an unauthenticated attacker to trigger catastrophic regex backtracking and exhaust server CPU. This issue is fixed in version 6.9.10.
Public exploit
A reference of the record is tagged as an exploit or proof of concept: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: a proof of concept is public.
Timeline
ID reserved
By GitHub_M
- 22 days later
· 22 days later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Analyzed | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.68% · top 47% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Weakness
Affected products
- affected < 6.9.10
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavenca.uhn.hapi.fhir:org.hl7.fhir.convertorsGHSA-fxj4-p9xp-37v5 (opens in a new tab)
- Mavenca.uhn.hapi.fhir:org.hl7.fhir.dstu2GHSA-fxj4-p9xp-37v5 (opens in a new tab)
- Mavenca.uhn.hapi.fhir:org.hl7.fhir.validationGHSA-fxj4-p9xp-37v5 (opens in a new tab)
- Mavenca.uhn.hapi.fhir:org.hl7.fhir.validation.cliGHSA-fxj4-p9xp-37v5 (opens in a new tab)
References (3)
- https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-fxj4-p9xp-37v5 (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/hapifhir/org.hl7.fhir.core/commit/56376f7986222626af061ca7fc27ee1ab030e590 (opens in a new tab)x_refsource_MISC
- https://github.com/hapifhir/org.hl7.fhir.core/releases/tag/6.9.10 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-fxj4-p9xp-37v5 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-55470)Record last updated .