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GHSA-8559-gwj3-q37r
No affected components available
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.
The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. The attacker needs the user to perform some action, like clicking a link. The vulnerability can affect other systems as well, not just the initial system. There is a high impact on the confidentiality of the information. There is a low impact on the integrity of the data.
Exploitation activity has been observed. Apply available patches or mitigations urgently.
Probability that this vulnerability will be exploited in the wild within the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
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