CVE-2026-93505 in SveltyCMS
Summary
by MITRE • 09/18/2026
A vulnerability was found in SveltyCMS 0.0.6. This vulnerability affects unknown code of the file src/utils/media/media-service.server.ts of the component SVG Media Upload. Performing a manipulation results in cross site scripting. The attack can be initiated remotely. The patch is named 05b4f9efeb79e9d72a693232334d7529687f896f. Applying a patch is the recommended action to fix this issue.
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Analysis
by VulDB Data Team • 09/18/2026
The identified vulnerability in SveltyCMS version 0.0.6 represents a significant security risk within its SVG media upload functionality, specifically located in the source file src/utils/media/media-service.server.ts. This flaw allows for cross-site scripting attacks when an attacker manipulates input data during the processing of uploaded files. The core issue stems from insufficient validation or sanitization of user-supplied content before it is processed by the server-side logic responsible for handling media uploads. Because this component deals with file ingestion, particularly SVGs which can contain embedded scripts and executable code, the lack of rigorous checks creates a pathway for malicious actors to inject harmful client-side script into web pages viewed by other users or administrators interacting with the CMS interface.
From a technical perspective, this vulnerability is classified under CWE-79, known as Improper Neutralization of Input During Web Page Generation, commonly referred to as Cross-Site Scripting (XSS). The attack vector is remote, meaning that an authenticated user or potentially any actor depending on authentication configurations can initiate the exploit without physical access to the system. When a maliciously crafted SVG file containing embedded JavaScript payloads is uploaded through this component, the application fails to properly sanitize the input before rendering it within the web interface. This allows the injected script to execute in the context of the victim's browser session, potentially leading to session hijacking, credential theft, defacement of the website content, or redirection to malicious sites that further compromise user systems.
The operational impact of this vulnerability is severe for organizations relying on SveltyCMS for content management. Successful exploitation can lead to unauthorized access to sensitive administrative functions if cookies or local storage tokens are stolen via script execution. It also undermines the integrity of the hosted web applications, as attackers can alter page contents dynamically. Furthermore, because SVG files are often used in visual contexts within CMS platforms, they may be displayed prominently on public-facing pages, increasing the likelihood that a broader audience will encounter and trigger the malicious payload if stored content is not properly sanitized upon retrieval or display. This extends the blast radius beyond just administrative users to regular site visitors as well.
To mitigate this risk, immediate application of patch 05b4f9efeb79e9d72a693232334d7529687f896f is strongly recommended by the developers. This update addresses the underlying code flaws in the media service module that allow unsanitized input to persist through the upload pipeline. In addition to applying the patch, administrators should implement defense-in-depth strategies such as enforcing strict file type validation on both client and server sides, ensuring that uploaded SVGs are stripped of all script tags and event handlers before storage or rendering. Utilizing a Content Security Policy (CSP) can also help mitigate the impact by restricting where scripts can be loaded from and executed within the application environment. Regular security audits and static code analysis focused on input handling in media processing modules should be conducted to prevent similar vulnerabilities in future updates, aligning with OWASP guidelines for secure web development practices.