CVE-2026-54087: EasyAdmin Cross-Site Scripting Vulnerability

HIGH
Advisory Identifier: GHSA-8559-gwj3-q37r
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CVSS 7.6
CWE-434 CWE-79
Published
Advisory Summary

CVE-2026-54087 is a HIGH (CVSS 7.6) cross-site scripting vulnerability (CWE-434: Unrestricted Upload of File with Dangerous Type) affecting EasyAdmin libraries in the Packagist ecosystem. The issue involves stored cross-site scripting (xss) via uploaded files served inline in filefield and imagefield. Remediation is available by upgrading affected packages to version 5.0.13.

CVE-2026-54087 at a Glance

CVE Identifier CVE-2026-54087
GHSA Identifier GHSA-8559-gwj3-q37r
Severity HIGH
CVSS v3.1 Base Score 7.6
CWE Classification CWE-434: Unrestricted Upload of File with Dangerous Type
Affected Product EasyAdmin
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 7.6

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-54087

To remediate this vulnerability, upgrade all affected EasyAdmin dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

easycorp/easyadmin-bundle fixed: 5.0.13 
Upgrade easycorp/easyadmin-bundle to 5.0.13
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for easycorp/easyadmin-bundle

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-54087, inspect your project dependencies for EasyAdmin:

inspect dependencies for easycorp/easyadmin-bundle

Analyze the terminal output to locate any version of EasyAdmin in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.0.13), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-434: Unrestricted Upload of File with Dangerous Type, where the product allows the upload or transfer of dangerous file types that are automatically processed within its environment. In EasyAdmin, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-54087 Affected EasyAdmin Versions

1 component(s)
Fixed Versions:
5.0.13
Product / Package Ecosystem Affected Versions Fixed Version
easycorp/easyadmin-bundle
 Packagist
≥ 5.0.0
< 5.0.13
5.0.13

References

GitHub Advisory / Wiki ADVISORY
https://github.com/EasyCorp/EasyAdminBundle/security/advisories/GHSA-8559-gwj3-q37r
Security Fix Commit FIX COMMIT
https://github.com/EasyCorp/EasyAdminBundle/commit/8132b2b0ca3876c9261264fa267106a1b2c10a68
EasyAdmin Source Repository REPOSITORY
https://github.com/EasyCorp/EasyAdminBundle
EasyAdmin Release RELEASE
https://github.com/EasyCorp/EasyAdminBundle/releases/tag/v5.0.13

Frequently Asked Questions

What is CVE-2026-54087?
CVE-2026-54087 is a security vulnerability in EasyAdmin involving Stored Cross-Site Scripting (XSS) via uploaded files served inline in FileField and ImageField under CWE-434: Unrestricted Upload of File with Dangerous Type.
Which EasyAdmin versions are affected?
Affected versions include releases prior to 5.0.13 across affected packages: easycorp/easyadmin-bundle.
What version fixes CVE-2026-54087?
Upgrading to 5.0.13 (or the latest patched release for your respective branch) resolves the vulnerability.
Is easycorp/easyadmin-bundle affected?
Yes, easycorp/easyadmin-bundle is affected in releases prior to 5.0.13. Upgrade your dependency to 5.0.13 or later.
What is the CVSS score of CVE-2026-54087?
CVE-2026-54087 has a CVSS v3.1 base score of 7.6 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N.
What CWE is associated with CVE-2026-54087?
CVE-2026-54087 is classified under CWE-434: Unrestricted Upload of File with Dangerous Type (The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.).
How can I check Packagist dependencies for CVE-2026-54087?
Run the dependency tree command: 'inspect dependencies for easycorp/easyadmin-bundle'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8559-gwj3-q37r",
  "modified" : "2026-07-14T19:51:35Z",
  "published" : "2026-07-14T19:51:34Z",
  "aliases" : [ "CVE-2026-54087" ],
  "summary" : "EasyAdmin: Stored Cross-Site Scripting (XSS) via uploaded files served inline in FileField and ImageField",
  "details" : "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`).\n\nAn 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.\n\nExploitation 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`.\n\nCredit\n\nWe would like to thank Emre Dogan for reporting the issue.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "easycorp/easyadmin-bundle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.0.0"
      }, {
        "fixed" : "5.0.13"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/EasyCorp/EasyAdminBundle/security/advisories/GHSA-8559-gwj3-q37r"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/EasyCorp/EasyAdminBundle/commit/8132b2b0ca3876c9261264fa267106a1b2c10a68"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/EasyCorp/EasyAdminBundle"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/EasyCorp/EasyAdminBundle/releases/tag/v5.0.13"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-434", "CWE-79" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-14T19:51:34Z",
    "nvd_published_at" : null
  }
}