CVE-2026-40076 Vulnerability Analysis & Exploit Details

CVE-2026-40076 Vulnerability Summary

CVE-2026-40076: OpenMRS Core is an open source electronic medical record system platform. In versions 2.7.8 and earlier and versions 2.8.0 through 2.8.5, the module upload endpoint at POST `/openmrs/ws/rest/v1/module` is vulnerable to a Zip Slip path traversal attack. During automatic extraction of uploaded .omod archives in `WebModuleUtil.startModule()`, ZIP entries under web/module/ are checked only to see whether the full entry path starts with `..,` and the remaining path is then concatenated into the destination path without normalization or a boundary check. A crafted archive can therefore include entries such as `web/module/../../../../malicious.jsp` and cause files to be written outside the intended module directory. An authenticated attacker with module upload access can write arbitrary files to locations such as the web application root and achieve remote code execution by uploading a JSP file and then requesting it. The issue is compounded by the fact that the module.allow_web_admin runtime property is enforced in the legacy UI controller but not in the REST API upload path, so deployments relying on that property to block web-based module administration remain exposed through the REST endpoint. This issue has been fixed in versions after 2.7.8 in the 2.7.x line and in version 2.8.6 and later.

CVE-2026-40076 References

External References

• https://github.com/openmrs/openmrs-core/security/advisories/GHSA-78fc-9688-w8xw
• https://github.com/openmrs/openmrs-core/security/advisories/GHSA-78fc-9688-w8xw

CWE Common Weakness Enumeration

CAPEC Common Attack Pattern Enumeration and Classification

• Path Traversal CAPEC-126 An adversary uses path manipulation methods to exploit insufficient input validation of a target to obtain access to data that should be not be retrievable by ordinary well-formed requests. A typical variety of this attack involves specifying a path to a desired file together with dot-dot-slash characters, resulting in the file access API or function traversing out of the intended directory structure and into the root file system. By replacing or modifying the expected path information the access function or API retrieves the file desired by the attacker. These attacks either involve the attacker providing a complete path to a targeted file or using control characters (e.g. path separators (/ or \) and/or dots (.)) to reach desired directories or files.
• Using Slashes and URL Encoding Combined to Bypass Validation Logic CAPEC-64 This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple ways of encoding a URL and abuse the interpretation of the URL. A URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
• Manipulating Web Input to File System Calls CAPEC-76 An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
• Using Escaped Slashes in Alternate Encoding CAPEC-78 This attack targets the use of the backslash in alternate encoding. An adversary can provide a backslash as a leading character and causes a parser to believe that the next character is special. This is called an escape. By using that trick, the adversary tries to exploit alternate ways to encode the same character which leads to filter problems and opens avenues to attack.
• Using Slashes in Alternate Encoding CAPEC-79 This attack targets the encoding of the Slash characters. An adversary would try to exploit common filtering problems related to the use of the slashes characters to gain access to resources on the target host. Directory-driven systems, such as file systems and databases, typically use the slash character to indicate traversal between directories or other container components. For murky historical reasons, PCs (and, as a result, Microsoft OSs) choose to use a backslash, whereas the UNIX world typically makes use of the forward slash. The schizophrenic result is that many MS-based systems are required to understand both forms of the slash. This gives the adversary many opportunities to discover and abuse a number of common filtering problems. The goal of this pattern is to discover server software that only applies filters to one version, but not the other.

Other 5 Recently Published CVEs Vulnerabilities

• CVE-2026-8288 – A vulnerability was determined in Open5GS up to 2.7.7. This affects the function gsm_handle_pdu_session_modification_qos_flow_descriptions of the f...
• CVE-2025-9973 – Due to not validating the organization context when executing adaptive authentication flows, the WSO2 Identity Server allows adaptive authenticatio...
• CVE-2025-10470 – The Magic Link authentication flow accepts multiple invalid authentication requests without adequate rate limiting or resource control, leading to ...
• CVE-2026-6956 – ATutor is vulnerable to Reflected XSS in /install/install.php endpoint. An attacker can provide a specially crafted URL that, when opened, results ...
• CVE-2026-6909 – ATutor is vulnerable to Reflected XSS in /install/upgrade.php endpoint. An attacker can provide a specially crafted URL that, when opened, results ...