Summary
EasyAdmin: Stored Cross-Site Scripting (XSS) via uploaded files served inline in FileField and ImageField
EasyAdmin's FileField and ImageField accept browser-executable file types by default (FileField applies no MIME/extension restrictions; ImageField's default Image constraint accepts SVG). When the upload directory is configured inside the public web root, as shown in the documentation, EasyAdmin links to the stored file inline (no download attribute or Content-Disposition: attachment).
An attacker with access to a form using these fields can upload an .html (FileField) or .svg (ImageField) file containing JavaScript. When another user opens it from the backend, it is served from the same origin and the script executes in the context of their authenticated admin session, enabling session/CSRF-token theft or privilege escalation.
Exploitation requires the developer to store uploads in the public directory and a privilege gap between the uploading user and the viewing administrator. This is stored XSS only, it does not allow remote code execution, because uploaded filenames are derived from Symfony's guessExtension(), which never produces .php/.phtml.
Credit
We would like to thank Emre Dogan for reporting the issue.
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.
CVE-2026-54087 has a CVSS score of 7.6 (High). The vector is network-reachable, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.0.13); upgrading removes the vulnerable code path.
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.
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Frequently Asked Questions
- What is CVE-2026-54087? CVE-2026-54087 is a high-severity cross-site scripting (XSS) vulnerability in easycorp/easyadmin-bundle (composer), affecting versions >= 5.0.0, < 5.0.13. It is fixed in 5.0.13. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- How severe is CVE-2026-54087? CVE-2026-54087 has a CVSS score of 7.6 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of easycorp/easyadmin-bundle are affected by CVE-2026-54087? easycorp/easyadmin-bundle (composer) versions >= 5.0.0, < 5.0.13 is affected.
- Is there a fix for CVE-2026-54087? Yes. CVE-2026-54087 is fixed in 5.0.13. Upgrade to this version or later.
- Is CVE-2026-54087 exploitable, and should I be worried? Whether CVE-2026-54087 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-2026-54087 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-2026-54087? Upgrade
easycorp/easyadmin-bundleto 5.0.13 or later.