Vulnerability record
CVE-2026-126436
The short answer
CVE-2026-126436 affects openemr openemr and is rated high (CVSS 8.7). It is not in CISA's Known Exploited Vulnerabilities catalog.
What it is
OpenEMR before 8.5.0 contains an authorization bypass vulnerability that allows OAuth2 clients to use unregistered grant types because oauth_clients.grant_types is never enforced. Attackers can request tokens with grant_type=password to bypass the user consent screen, and disabled clients can redeem authorization codes using JWT client assertions.
Weakness: CWE-862.
Severity
8.7 high
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Exploited (CISA KEV)
Not listed
CISA lists confirmed exploitation only
EPSS, next 30 days
No score
FIRST scores CVEs within a day of publication
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Affected products
openemr. NVD's record lists the exact affected versions.
References
Questions
Is CVE-2026-126436 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog as of 2026-11-13.
How do I fix CVE-2026-126436?
Follow the vendor advisory in the references below. NVD lists the affected versions under its configurations.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Awaiting Analysis. The description is NVD's text, quoted as published.
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