Cyber Resilience

CVE-2026-34055

Access Control in Open-Emr Openemr ≤ 8.0.0.3

Published
26 March 2026
Modified
26 March 2026
Patch / advisory
CVSS Score v3.1 8.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0027 19th percentile
Risk Priority 58 floored blend · peak EPSS

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 Exploit Public-Facing Application (T1190); ranked at the 19th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-3 (Access Enforcement) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

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.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-25745Same product: Open-Emr Openemr
CVE-2026-32120Same product: Open-Emr Openemr
CVE-2026-27943Same product: Open-Emr Openemr
CVE-2026-25927Same product: Open-Emr Openemr
CVE-2026-25930Same product: Open-Emr Openemr
CVE-2026-33931Same product: Open-Emr Openemr
CVE-2026-25744Same product: Open-Emr Openemr
CVE-2026-25929Same product: Open-Emr Openemr
CVE-2026-25147Same product: Open-Emr Openemr
CVE-2026-25220Same product: Open-Emr Openemr

Affected Assets

open-emr
openemr
≤ 8.0.0.3

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Enforcing approved authorizations on every access request structurally stops a user-controlled key from reaching another user's data.

Requiring explicit access-control decisions on each request blocks unauthorized key-driven access.

Least-privilege restrictions limit the scope of data reachable even if a key check is bypassed.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 full match
prevents

Enforcing authorization policy and least privilege directly blocks user-controlled key tampering that bypasses access checks.

PR.IR-01 mostly match
prevents

Logical access controls prevent unauthorized data access that results from missing authorization checks on object references.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect missing authorization checks but does not prevent the weakness in production.

prevents

Information access restriction explicitly enforces that users may only retrieve data they are authorized to see, directly addressing user-controlled key bypass.

prevents

Access control policy directly requires enforcement of authorization rules that prevent unauthorized access via manipulated keys.

prevents

Managing access rights includes ensuring users can only access their own records and not bypass authorization by altering identifiers.

mitigates

Privileged access rights control restricts what data each user may access, mitigating direct object reference attacks.

prevents

Secure development lifecycle includes authorization design but does not itself implement runtime access checks.

References