CVE-2026-34055
Published: 26 March 2026
Summary
CVE-2026-34055 is a high-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Open-Emr Openemr. Its CVSS base score is 8.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 2.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and SI-10 (Information Input Validation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Enforces approved authorizations for access to patient notes, directly preventing unauthorized updates and deletes via unverified note IDs.
Validates user-supplied note IDs to ensure they belong to patients the user is authorized to access, blocking IDOR exploitation.
Implements security attributes like patient ownership on notes to support enforcement of access controls against unauthorized manipulation.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
IDOR in public-facing web app (OpenEMR) directly enables network exploitation (T1190) by authenticated low-priv users to access/modify unauthorized patient data (T1213), achieving horizontal privilege escalation (T1068) via stored data manipulation (T1565).
NVD Description
OpenEMR is a free and open source electronic health records and medical practice management application. Prior to version 8.0.0.3, the legacy patient notes functions in `library/pnotes.inc.php` perform updates and deletes using `WHERE id = ?` without verifying that the note…
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belongs to a patient the user is authorized to access. Multiple web UI callers pass user-controlled note IDs directly to these functions. This is the same class of vulnerability as CVE-2026-25745 (REST API IDOR), but affects the web UI code paths. Version 8.0.0.3 patches the issue.
Deeper analysisAI
CVE-2026-34055 is an Insecure Direct Object Reference (IDOR) vulnerability (CWE-639) in OpenEMR, a free and open-source electronic health records and medical practice management application. Versions prior to 8.0.0.3 are affected, specifically the legacy patient notes functions in `library/pnotes.inc.php`. These functions perform SQL updates and deletes using a `WHERE id = ?` clause without verifying that the targeted note belongs to a patient the user is authorized to access. Multiple web UI callers pass user-controlled note IDs directly to these functions, enabling unauthorized manipulation. This mirrors the IDOR issue in CVE-2026-25745, which affected REST API endpoints, but targets web UI code paths instead.
The vulnerability has a CVSS v3.1 base score of 8.1 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N), indicating exploitation over the network by low-privileged authenticated users with low complexity and no user interaction required. Attackers can supply arbitrary note IDs to update or delete sensitive patient notes belonging to other users or patients, potentially exposing or altering confidential medical data and compromising record integrity.
OpenEMR version 8.0.0.3 addresses the issue with a targeted patch. Security advisories recommend immediate upgrades to this version or later. Key resources include the patching commit at https://github.com/openemr/openemr/commit/214c9b4585a6f1c8c22750172d47f0e258fec0bf, the release notes at https://github.com/openemr/openemr/releases/tag/v8_0_0_3, and the GitHub security advisory at https://github.com/openemr/openemr/security/advisories/GHSA-8gj5-r8vm-mghq.
Details
- CWE(s)