CVE-2026-24847: 
OpenEMR vulnerability analysis and mitigation

CVE-2026-24847 is an open redirect vulnerability in the Eye Exam form module of OpenEMR, a widely used open-source electronic health records (EHR) and medical practice management application. The flaw affects all OpenEMR versions up to and including 7.0.4 (prior to 8.0.0) and was disclosed on February 25, 2026, with a fix released in version 8.0.0. It carries a CVSS v3.1 base score of 6.1 (Medium), assigned by GitHub Security (GitHub Advisory). The vulnerability was reported by researcher DenizParlak (GitHub Advisory).

The root cause is improper input validation classified as CWE-601 (URL Redirection to Untrusted Site / Open Redirect). The vulnerable file interface/forms/eye_mag/view.php directly uses the user-supplied url parameter from $_REQUEST in an HTTP Location header without any sanitization or allowlist validation, as shown in the vulnerable code snippet: if (!empty($_REQUEST['url'])) { header('Location: ' . $_REQUEST['url']); exit; } (GitHub Advisory). An attacker can craft a URL pointing to this endpoint with an arbitrary external destination, and any authenticated user who clicks the link will be silently redirected to the attacker-controlled site. The fix, committed in b924459, simply removes the entire redirect block from the file (GitHub Commit).

Successful exploitation enables phishing attacks targeting healthcare providers and staff using OpenEMR, potentially leading to credential theft and unauthorized access to sensitive patient health information. Because OpenEMR handles protected health information (PHI), credential compromise could result in HIPAA compliance violations and significant regulatory exposure. The vulnerability has low impact on confidentiality and integrity (no direct data access or modification), and no availability impact, but the healthcare context amplifies the real-world risk of social engineering attacks (GitHub Advisory).

A proof-of-concept exploit is publicly documented in the GitHub Security Advisory, demonstrating that a simple crafted URL (e.g., http://target/interface/forms/eye_mag/view.php?url=https://evil.com/) triggers a 302 redirect to an arbitrary external site (GitHub Advisory). Exploitation requires the victim to be authenticated to OpenEMR and to click the malicious link, but the attacker themselves does not need any privileges. There is no evidence of in-the-wild exploitation at this time, and the EPSS score is approximately 0.027% (Feedly). The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

1. Reconnaissance: Identify OpenEMR instances running versions prior to 8.0.0 (up to 7.0.4) that are accessible over the network, using search engines, Shodan, or internal network scanning.
2. Craft malicious URL: Construct a redirect URL targeting the vulnerable endpoint with an attacker-controlled destination, e.g., http://<openemr-host>/interface/forms/eye_mag/view.php?url=https://attacker-phishing-site.com/.
3. Deliver the link: Send the crafted URL to a target healthcare provider via email, internal messaging, or another social engineering channel, making it appear to originate from a trusted OpenEMR context.
4. Victim clicks link: The authenticated OpenEMR user clicks the link while logged in; the server responds with HTTP/1.1 302 Found and Location: https://attacker-phishing-site.com/, transparently redirecting the victim's browser.
5. Phishing/credential harvest: The victim lands on the attacker's site (which may mimic the OpenEMR login page or another trusted service), where credentials or other sensitive information can be harvested (GitHub Advisory).

• Network: HTTP GET or POST requests to /interface/forms/eye_mag/view.php containing a url parameter pointing to an external domain; HTTP 302 responses from the OpenEMR server with a Location header pointing to non-OpenEMR domains.
• Logs: Web server access logs showing requests such as GET /interface/forms/eye_mag/view.php?url=https://external-site.com/ from authenticated sessions; unusual referrer chains in logs where users arrive at external sites from OpenEMR.
• Application Logs: OpenEMR audit logs showing authenticated user sessions accessing the Eye Exam form module (eye_mag/view.php) with unexpected url parameters.

The primary remediation is to upgrade OpenEMR to version 8.0.0 or later, which removes the vulnerable redirect code block entirely from interface/forms/eye_mag/view.php (GitHub Commit). For organizations unable to patch immediately, network-level controls (e.g., web application firewall rules) should be configured to block or alert on requests to /interface/forms/eye_mag/view.php containing a url parameter with external destinations. Additionally, healthcare staff should be educated about phishing risks and trained to verify URLs before clicking links within the application (GitHub Advisory).