# HAPI FHIR: ReDoS via FHIRPath matches()/replaceMatches() in FHIR Validator HTTP Endpoint Advisory record · `GHSA-3653-68v6-rq57` - **Identifiers:** `GHSA-3653-68v6-rq57` · `CVE-2026-45367` - **State:** Confirmed - **Severity:** CVSS 7.5 High - **Critical:** No - **Weakness (CWE):** [CWE-1333](https://cwe.mitre.org/data/definitions/1333.html) - **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md) - **Published:** 18 May 2026 - **Updated:** 10 Sept 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 18 May 2026, 20:23 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `ca.uhn.hapi.fhir:org.hl7.fhir.dstu2` (Maven): affected `<6.9.7`; fixed in `6.9.7` - `ca.uhn.hapi.fhir:org.hl7.fhir.dstu2016may` (Maven): affected `<6.9.7`; fixed in `6.9.7` - `ca.uhn.hapi.fhir:org.hl7.fhir.dstu3` (Maven): affected `<6.9.7`; fixed in `6.9.7` - `ca.uhn.hapi.fhir:org.hl7.fhir.r4` (Maven): affected `<6.9.7`; fixed in `6.9.7` - `ca.uhn.hapi.fhir:org.hl7.fhir.r4b` (Maven): affected `<6.9.7`; fixed in `6.9.7` - `ca.uhn.hapi.fhir:org.hl7.fhir.r5` (Maven): affected `<6.9.7`; fixed in `6.9.7` - `ca.uhn.hapi.fhir:org.hl7.fhir.validation` (Maven): affected `<6.9.7`; fixed in `6.9.7` - `ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli` (Maven): affected `<6.9.7`; fixed in `6.9.7` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > HAPI FHIR's FHIRPath engine, in the org.hl7.fhir packages for dstu2, dstu2016may, dstu3, r4, r4b, r5, validation, and validation.cli before 6.9.7, passes user-supplied regular expressions from matches(), matchesFull() and replaceMatches() directly to Java regex functions with no complexity limit or timeout. An attacker who can submit a resource to a validator that evaluates such expressions can supply a pattern that causes catastrophic backtracking, exhausting CPU and causing denial of service. Upgrade to version 6.9.7 or later. The source gives no workaround. Written 2 Nov 2026. ## Not analysed yet We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check. ## Severity and exploitation - 7.5 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.0068, the 52nd percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 31 Oct 2026, 14:16 UTC: First seen by agentprime - 31 Oct 2026, 14:16 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-3653-68v6-rq57) ## Sources - [GitHub Advisory Database: GHSA-3653-68v6-rq57](https://github.com/advisories/GHSA-3653-68v6-rq57) - [OSV: GHSA-3653-68v6-rq57](https://osv.dev/vulnerability/GHSA-3653-68v6-rq57) - - Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code. ## Check whether this affects you A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet. - With the agentprime MCP server (), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .