Summary
ThingsBoard in versions prior to v4.2.1 allows an authenticated user to upload malicious SVG images via the "Image Gallery", leading to a Stored Cross-Site Scripting (XSS) vulnerability. The exploit can be triggered when any user accesses the public API endpoint of the malicious SVG images, or if the malicious images are embedded in an iframe element, during a widget creation, deployed to any page of the platform (e.g., dashboards), and accessed during normal operations. The vulnerability resides in the ImageController, which fails to restrict the execution of JavaScript code when an image is loaded by the user's browser. This vulnerability can lead to the execution of malicious code in the context of other users' sessions, potentially compromising their accounts and allowing unauthorized actions.
Impact
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2025-3261? CVE-2025-3261 is a medium-severity cross-site scripting (XSS) vulnerability in org.thingsboard:application (maven), affecting versions < 4.2.1. It is fixed in 4.2.1. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- Which versions of org.thingsboard:application are affected by CVE-2025-3261? org.thingsboard:application (maven) versions < 4.2.1 is affected.
- Is there a fix for CVE-2025-3261? Yes. CVE-2025-3261 is fixed in 4.2.1. Upgrade to this version or later.
- Is CVE-2025-3261 exploitable, and should I be worried? Whether CVE-2025-3261 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-3261 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-3261? Upgrade
org.thingsboard:applicationto 4.2.1 or later.