CVE-2026-37710 in Omeka
Summary
by MITRE • 08/28/2026
Cross Site Scripting vulnerability in Omeka S v.4.2.0 allows a remote attacker to execute arbitrary code via the site navigation custom URL function
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Analysis
by VulDB Data Team • 08/28/2026
The identified security flaw resides within the Omeka S content management platform, specifically affecting version 4.2.0 and potentially earlier iterations that share this architectural pattern. This vulnerability is classified as a Cross-Site Scripting (XSS) issue, which falls under the broader category of injection flaws where untrusted data is sent to an interpreter without proper validation or encoding. The specific vector for exploitation involves the site navigation custom URL function, a feature designed to allow administrators and potentially other authorized users to define custom links within the website's navigation menu. When this functionality processes user-supplied input, it fails to adequately sanitize or encode special characters that have semantic meaning in HTML contexts, such as angle brackets, quotation marks, and ampersands. This lack of rigorous output encoding creates a pathway for malicious actors to inject client-side scripts into web pages viewed by other users.
From a technical perspective, the root cause is a classic case of stored or reflected XSS depending on how the custom URL data persists within the application's database and subsequent rendering engine. If an attacker can manipulate the input field associated with the site navigation URL, they can embed JavaScript code that executes in the context of the victim's browser session when the page loads. This execution occurs because the web server returns the unsanitized payload as part of the HTML response, leading the client-side interpreter to treat the malicious script as legitimate content rather than data. The vulnerability exploits the trust a user has in the website by leveraging the application itself to deliver hostile code directly into their browser environment.
The operational impact of this vulnerability is significant due to its potential for session hijacking and credential theft. An attacker who successfully exploits this flaw can execute arbitrary JavaScript commands on behalf of any victim who views the compromised navigation menu or page containing the injected script. This capability allows the adversary to steal sensitive information such as authentication cookies, session tokens, and personally identifiable information stored in local storage or form fields. Furthermore, the malicious code could perform actions on behalf of the user without their knowledge, such as changing account settings, making unauthorized requests to internal APIs, or defacing the website's appearance. In environments where Omeka S is used for institutional archives or educational resources, this breach compromises not only individual privacy but also the integrity and reputation of the hosting organization.
This vulnerability aligns with CWE-79, which describes Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. It also maps to MITRE ATT&CK technique T1059, specifically sub-technique 007 for JavaScript execution, and potentially T1204 if used in conjunction with user execution tactics where social engineering might be employed to lure victims into clicking a crafted link or visiting a compromised page. The exploitation relies on the attacker's ability to inject code that is then executed by the victim's browser, highlighting the critical importance of context-aware output encoding and input validation mechanisms within web application development lifecycles.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. For administrators using Omeka S v4.2.0, it is imperative to apply any available patches or updates released by the vendor that address this specific sanitization gap in the navigation URL handling logic. If a patch is not immediately available, temporary workarounds may include restricting access to the site administration interface through IP whitelisting or multi-factor authentication to reduce the attack surface for those with write privileges. From a development standpoint, implementing strict output encoding based on the context of the data insertion point is essential. This involves ensuring that all user-supplied input intended for HTML attributes or body content is encoded using appropriate libraries that handle character escaping correctly. Additionally, deploying Content Security Policy headers can help mitigate the impact by restricting the sources from which scripts are allowed to load and execute, thereby preventing many types of XSS attacks even if injection occurs. Regular security audits and static code analysis tools should be integrated into the development process to detect such input validation failures before deployment.