CVE
OpenEMR authorization bypass in OAuth scope checks
Affects OpenEMR before 8.4.0 with the FHIR API and system scopes API enabled and the default automatic patient-app approval. Fixed in 8.4.0.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 8.4.0
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Affected OpenEMR versions are before 8.4.0; the advisory tested 8.3.0. The FHIR API must be enabled (rest_fhir_api=1). System scopes API must be enabled (rest_system_scopes_api=1). Automatic patient-app approval mode is used (oauth_app_manual_approval=0), which is the default. OAuth registration, token, and FHIR routes must be network reachable.
- Published
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.46% · 40th percentile
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 21/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
OpenEMR before 8.4.0 contains OAuth scope canonicalization and containment flaws that allow unauthenticated attackers to obtain unapproved system-level FHIR access. Attackers can register a colon-form system:Patient.read client that bypasses approval, then request unregistered system/Patient.write scope to read, modify, and create Patient records.
Who should check
Teams running OpenEMR before 8.4.0 with the FHIR API and system scopes enabled, including sites using the official openemr/openemr Docker image.
Not fixed by: Fixing only the containment logic does not repair the approval bypass.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure12/25Specific setups only, reachable over the network without a login
- Reach?/20Unknown. No tracked technology or package matched
- Severity9.3/10CVSS 9.3
- No patch0/5No signal
What would change the score
- Would score about 71 if added to CISA KEV
- Would score about 66 if CISA's SSVC rates exploitation active
What to do
Check whether your setup matches what the bug needs.
Affected OpenEMR versions are before 8.4.0; the advisory tested 8.3.0. The FHIR API must be enabled (rest_fhir_api=1). System scopes API must be enabled (rest_system_scopes_api=1). Automatic patient-app approval mode is used (oauth_app_manual_approval=0), which is the default. OAuth registration, token, and FHIR routes must be network reachable.Upgrade to a fixed version: 8.4.0.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-126473 (OpenEMR before 8.4.0 OAuth Authorization Bypass via Scope Canonicalization), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-126473 (entry last updated 2026-11-13):
Affected:
- openemr openemr: fixed in 8.4.0
Fixed versions: 8.4.0.
Conditions (all must be true for the bug to be hit):
- Affected OpenEMR versions are before 8.4.0; the advisory tested 8.3.0. (source: https://github.com/openemr/openemr/security/advisories/GHSA-6xh3-fmm5-jjp4)
- The FHIR API must be enabled (rest_fhir_api=1). (source: https://github.com/openemr/openemr/security/advisories/GHSA-6xh3-fmm5-jjp4)
- System scopes API must be enabled (rest_system_scopes_api=1). (source: https://github.com/openemr/openemr/security/advisories/GHSA-6xh3-fmm5-jjp4)
- Automatic patient-app approval mode is used (oauth_app_manual_approval=0), which is the default. (source: https://github.com/openemr/openemr/security/advisories/GHSA-6xh3-fmm5-jjp4)
- OAuth registration, token, and FHIR routes must be network reachable. (source: https://github.com/openemr/openemr/security/advisories/GHSA-6xh3-fmm5-jjp4)
Setup: the bug needs a feature or setting that is off by default or uncommon. Check whether each asset has it on.
Attacker needs: network access, no login, no user action.
CISA KEV: CVE-2026-126473 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-126473 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/openemr/openemr/security/advisories/GHSA-6xh3-fmm5-jjp4
- https://www.vulncheck.com/advisories/openemr-before-8.4.0-oauth-authorization-bypass-via-scope-canonicalization
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-126473
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-126473"}.Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now
Affected versions
- openemr openemr
fixed in 8.4.0
Evidence 4
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-126473
Is CVE-2026-126473 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
Two OAuth scope authorization flaws allow unauthenticated attackers to obtain unapproved system-level FHIR access, which permits reading, modifying and creating Patient records.Source: github.com, vulncheck.com
Which versions are affected by CVE-2026-126473?
openemr: before 8.4.0.Source: cve.now feed data
Am I affected, and how do I check?
OpenEMR versions before 8.4.0 are affected; the advisory tested 8.3.0. The setup also needs the FHIR API (rest_fhir_api=1) and system scopes API (rest_system_scopes_api=1) enabled, automatic patient-app approval (oauth_app_manual_approval=0, the default), and network-reachable OAuth registration, token, and FHIR routes. Check the OpenEMR version and these settings in the configuration.Source: github.com, vulncheck.com
How do I fix CVE-2026-126473?
Upgrade to OpenEMR 8.4.0 or later, which is the fixed version for this vulnerability.Source: github.com, vulncheck.com