Cyber Resilience

CVE-2026-33302

Access Control in Open-Emr Openemr ≤ 8.0.0.2

Public PoCAccess Control
Published
19 March 2026
Modified
20 March 2026
Patch / advisory
CVSS Score v4 7.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P/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
EPSS Score 0.0032 24th percentile
Risk Priority 36 floored blend · peak EPSS

Summary

CVE-2026-33302 is a high-severity Incorrect Authorization (CWE-863) vulnerability in Open-Emr Openemr. Its CVSS base score is 7.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 24th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — 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-2026-33302 is a vulnerability in OpenEMR, a free and open source electronic health records and medical practice management application. In versions prior to 8.0.0.2, the ACL module's `AclMain::zhAclCheck()` function fails to properly enforce access control by only checking for the presence of any "allow" setting on a user or group, while ignoring explicit "deny" settings (allowed=0). This allows access to be granted if a user belongs to any group with an "allow," overriding administrator-intended denies. The issue is classified under CWE-863 (Incorrect Authorization) with 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).

An attacker with low privileges (PR:L), such as an authenticated user, can exploit this over network (AV:N) with low complexity and no user interaction required. If an administrator attempts to revoke access by setting an explicit deny on the user or their group, but the user remains in another group with an "allow," the vulnerability permits unauthorized access. This results in high confidentiality (C:H) and integrity (I:H) impacts, potentially allowing the attacker to view or modify sensitive electronic health records and medical data beyond their intended permissions, while availability remains unaffected (A:N).

The OpenEMR security advisory (GHSA-v68v-pwc4-8p2m) and corresponding fix in commit 0ef9b1763029e52d43fcb4fd0ebb0769a7ec43d4 confirm that upgrading to version 8.0.0.2 resolves the issue by ensuring explicit denies are properly evaluated in the ACL check. Security practitioners should prioritize patching affected OpenEMR instances and review existing ACL configurations to verify enforcement of denies after remediation.

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 8.0.0.2, the module ACL function `AclMain::zhAclCheck()` only checks for the presence of any "allow" (user or group). It never checks for explicit "deny"…

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(allowed=0). As a result, administrators cannot revoke access by setting a user or group to "deny"; if the user is in a group that has "allow," access is granted regardless of explicit denies. Version 8.0.0.2 fixes the issue.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
T1548.002 Bypass User Account Control Privilege Escalation
Adversaries may bypass UAC mechanisms to elevate process privileges on system.
T1548.003 Sudo and Sudo Caching Privilege Escalation
Adversaries may perform sudo caching and/or use the sudoers file to elevate privileges.
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.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-25127Same product: Open-Emr Openemr
CVE-2026-32123Same product: Open-Emr Openemr
CVE-2026-24487Same product: Open-Emr Openemr
CVE-2026-24890Same product: Open-Emr Openemr
CVE-2026-34056Same product: Open-Emr Openemr
CVE-2023-2950Same product: Open-Emr Openemr
CVE-2026-34051Same product: Open-Emr Openemr
CVE-2026-33304Same product: Open-Emr Openemr
CVE-2026-33915Same product: Open-Emr Openemr
CVE-2026-33305Same product: Open-Emr Openemr

Affected Assets

open-emr
openemr
≤ 8.0.0.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

AC-3 directly requires correct enforcement of authorization decisions on every access request, structurally preventing incorrect checks.

AC-24 ensures access-control decisions are made and applied consistently, reducing the chance of an incorrect authorization result.

A reference monitor that is always invoked and tamper-proof forces every authorization decision through a verified, correct path.

Least-privilege assignments shrink the set of authorizations that must be checked correctly, limiting exposure to flawed checks.

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 mostly match
prevents

Defining, enforcing, and reviewing access authorizations and least privilege directly prevents incorrect authorization checks.

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.

prevents

Requiring consistency between access rights and classification plus formal approval steps ensures that the authorization logic correctly distinguishes between entities that should and should not be granted access.

prevents

Enforcing policy-driven approval and role-change reviews stops incorrect or stale authorization decisions from remaining in effect after job changes or terminations.

prevents

By tying access rights to identity, device, location and classification, the control reduces the likelihood that an authorization decision will be based on an incorrect or bypassed policy.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-863
  • V-252656 The OL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863
RHEL 7 (1 rule)
  • V-204430 The Red Hat Enterprise Linux operating system must be configured so that users must re-authenticate for privilege escalation. prevents CWE-863
RHEL 8 (1 rule)
  • V-251712 The RHEL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863

References