Sign in
Deutsch English Español Polski
Medium

Craft CMS: Sensitive File Disclosure / Server-Side File Read

  • Disclosed: 06.07.2026
  • Updated: 11.10.2026 10:22

The dataUrl() Twig function is included in Craft’s Twig sandbox allowlist, allowing any control panel user granted the utility:system-messages permission to embed a file-reading payload into system email templates. When those emails are sent, the server reads the target file and returns its contents as a base64-encoded data URL embedded in the email body. The .env file, which typically contains the database password, CRAFT_SECURITY_KEY, and third-party API keys, passes all of Craft’s existing dataUrl() protection checks and is fully exfiltrated. Obtaining CRAFT_SECURITY_KEY enables an attacker to forge session tokens and escalate to full admin account takeover.

Details

Affected versions: Craft CMS 4.x, 5.x (confirmed against 5.9.19)

The vulnerability arises from the combination of three code facts:

  1. dataUrl is in the Twig sandbox allowlist src/config/twig-sandbox.php, line 115: php'allowedFunctions' => [ ... 'dataUrl', // ← allows file reading inside sandboxed templates ... ],

  2. Html::dataUrl() does not block dotfiles src/helpers/Html.php, lines 1065–1090. The function applies four checks before reading a file:

Must be within the project root .env is at the root Must not be in a system directory (config/, vendor/, storage/, templates/) .env is not Must not be a .php file .env has no extension File must exist .env always exists in a Craft install

There is no check for dotfiles or specifically for .env. All four checks pass silently and file_get_contents() is called, with the result returned as data:text/plain;base64,....

  1. System message body is rendered via renderSandboxedString() src/mail/Mailer.php, lines 181–183: php$subject = $view->renderSandboxedString($systemMessage->subject, $variables); $textBody = $view->renderSandboxedString($systemMessage->body, $variables); $htmlBody = $view->renderSandboxedString($systemMessage->body, $variables, escapeHtml: true);

Any body content saved to a system message is executed inside the Twig sandbox when the email renders. Because dataUrl is in allowedFunctions, the sandbox policy permits its execution without restriction.

Access control: The utility:system-messages permission is a non-admin CP permission grantable to any user group via Settings > Users > Groups. It is not restricted to admins.

Impact

Vulnerability type: Sensitive File Disclosure / Server-Side File Read Who is impacted: Any Craft CMS 4.x or 5.x installation where at least one non-admin control panel user has been granted the utility:system-messages permission, and email sending is configured.

Resources:

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package craftcms/cms >= 4.0.0-RC1, < 4.18.0, >= 5.0.0-RC1, < 5.10.0 4.18.0, 5.10.0

References

CVSS score -
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness (CWE)
CWE-200
Platform
Composer
Package
craftcms/cms
Disclosed
06.07.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-287w-mxq6-x2cp - CC BY 4.0

Vulnerability history: craftcms/cms

All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (127) in the archive
Total entries
127
First → latest
07.2021 08.2026
Without a fix
6
Exploited in attacks
4

Severity breakdown

  • Critical 9
  • High 41
  • Medium 65
  • Low 12

Disclosures per year

Severity:
  1. Craft CMS: Passkey login accepts replayed WebAuthn assertions
    Critical CVE-2026-72780 >= 5.0.0-RC1, < 5.10.5 5.10.5
  2. Craft CMS: Arbitrary user password reset leading to administrator account takeover
    High CVE-2026-72786 >= 5.0.0-RC1, < 5.10.8 5.10.8
  3. Craft CMS: Authenticated RCE through Twig sandbox escape
    High CVE-2026-72781 >= 5.0.0-RC1, < 5.10.7, >= 4.0.0-RC1, < 4.18.3 5.10.7, 4.18.3
  4. Craft CMS: Authenticated RCE via `condition.config` JSON cleanse bypass
    High CVE-2026-72778 >= 5.0.0-RC1, < 5.10.6, >= 4.0.0-RC1, < 4.18.2 5.10.6, 4.18.2
  5. Craft CMS: RCE via missing cleanseConfig in FieldsController::actionRenderCardPreview
    High CVE-2026-56382 >= 5.5.0, < 5.9.14 5.9.14
  6. Craft CMS: Potential authenticated Remote Code Execution via referrer redirect
    High CVE-2026-55794 >= 5.9.0, < 5.10.0 5.10.0
  7. Craft CMS: Sensitive File Disclosure / Server-Side File Read this entry
    Medium CVE-2026-55792 >= 4.0.0-RC1, < 4.18.0, >= 5.0.0-RC1, < 5.10.0 4.18.0, 5.10.0
  8. Craft CMS: DOM XSS via GitHub issue title in CraftSupport widget
    High CVE-2026-55790 >= 5.0.0-RC1, < 5.9.23, >= 4.0.0-RC1, < 4.17.16 5.9.23, 4.17.16
  9. Craft CMS Vulnerable to Unauthorized Deletion of Destination Folders During Forced Moves
    High CVE-2026-50282 >= 5.0.0-RC1, < 5.9.21, >= 4.0.0-RC1, < 4.17.14 5.9.21, 4.17.14
  10. Craft CMS's mass assignment via id in newAttributes during bulk duplicate overwrites existing elements
    High CVE-2026-50281 >= 5.7.0, < 5.9.21 5.9.21
  11. Craft CMS: Missing peer-permission check in `AssetsController::actionDeleteFolder` allows deletion of other users' assets
    High CVE-2026-50284 >= 5.0.0-RC1, < 5.9.22, >= 4.0.0-RC1, < 4.17.15 5.9.22, 4.17.15
  12. Craft CMS: Authorship spoofing in `entries/save-entry` via pre-check/post-mutation authorization gap
    High CVE-2026-50279 >= 5.0.0-RC1, < 5.9.21 5.9.21
  13. Craft CMS: Blind SSRF and Arbitrary JavaScript Injection via Host Header Poisoning in actionResourceJs
    Critical CVE-2026-55791 >= 5.0.0-RC1, < 5.10, >= 4.0.0-RC1, < 4.18 5.10, 4.18
  14. Craft CMS's Missing Volume Permission Check in AssetsController::actionShowInFolder Allows Information Disclosure
    High CVE-2026-44012 >= 5.0.0-RC1, < 5.9.18 5.9.18
  15. Craft CMS has Potential Authenticated Remote Code Execution via Malicious Attached Behavior
    High CVE-2026-44011 >= 4.0.0, < 4.17.12, >= 5.0.0, < 5.9.18 4.17.12, 5.9.18
  16. Craft CMS's Missing Authorization in GraphQL Address Resolver Allows Cross-Scope PII Disclosure
    High CVE-2026-44010 >= 5.0.0, < 5.9.18, >= 4.0.0, < 4.17.12 5.9.18, 4.17.12
  17. Craft CMS is Vulnerable to Authenticated Remote Code Execution via Malicious Attached Behavior
    High CVE-2026-33157 >= 5.6.0, < 5.9.13 5.9.13
  18. Craft CMS Vulnerable to Privilege Escalation/Bypass through UsersController->actionImpersonateWithToken()
    High CVE-2026-32267 >= 4.0.0-RC1, < 4.17.6, >= 5.0.0-RC1, < 5.9.12 4.17.6, 5.9.12
  19. Craft CMS vulnerable to behavior injection RCE ElementIndexesController and FieldsController
    High CVE-2026-32264 >= 4.0.0-RC1, < 4.17.5, >= 5.0.0-RC1, < 5.9.11 4.17.5, 5.9.11
  20. Craft CMS vulnerable to behavior injection RCE via EntryTypesController
    High CVE-2026-32263 >= 5.6.0, < 5.9.11 5.9.11
  21. CraftCMS has an RCE vulnerability via relational conditionals in the control panel
    High CVE-2026-31857 >= 5.0.0-RC1, < 5.9.9, >= 4.0.0-beta.1, < 4.17.4 5.9.9, 4.17.4
  22. CraftCMS's `ElementSearchController` Affected by Blind SQL Injection
    High CVE-2026-31858 >= 5.0.0-RC1, < 5.9.9 5.9.9
  23. Craft CMS has unauthenticated activation email trigger with potential user enumeration
    High CVE-2026-29069 >= 5.0.0-RC1, < 5.9.0-beta.2, >= 4.0.0-RC1, < 4.17.0-beta.2 5.9.0-beta.2, 4.17.0-beta.2
  24. Craft CMS Vulnerable to Authenticated RCE via "craft.app.fs.write()" in Twig Templates
    Critical CVE-2026-28697 >= 5.0.0-RC1, < 5.9.0-beta.1, >= 4.0.0-RC1, < 4.17.0-beta.1 5.9.0-beta.1, 4.17.0-beta.1
  25. Craft CMS has IDOR via GraphQL @parseRefs
    High CVE-2026-28696 >= 4.0.0-RC1, < 4.17.0-beta.1, >= 5.0.0-RC1, < 5.9.0-beta.1 4.17.0-beta.1, 5.9.0-beta.1
  26. Craft CMS has Cloud Metadata SSRF Protection Bypass via DNS Rebinding
    High CVE-2026-27127 >= 5.0.0-RC1, < 5.8.23, >= 3.5.0, < 4.16.19 5.8.23, 4.16.19
  27. Craft CMS Vulnerable to potential authenticated Remote Code Execution via malicious attached Behavior
    High CVE-2026-25498 >= 5.0.0-RC1, < 5.8.22, >= 4.0.0-RC1, < 4.16.18 5.8.22, 4.16.18
  28. Craft CMS: GraphQL Asset Mutation Privilege Escalation
    High CVE-2026-25497 >= 5.0.0-RC1, < 5.9.0-beta.1, >= 4.0.0-RC1, < 4.17.0-beta.1 5.9.0-beta.1, 4.17.0-beta.1
  29. Craft CMS Vulnerable to SQL Injection in Element Indexes via `criteria[orderBy]`
    High CVE-2026-25495 >= 5.0.0-RC1, < 5.8.22, >= 4.0.0-RC1, < 4.16.18 5.8.22, 4.16.18
  30. Craft CMS vulnerable to potential authenticated Remote Code Execution via malicious attached Behavior
    High CVE-2025-68455 >= 5.0.0-RC1, < 5.8.21, >= 4.0.0-RC1, < 4.16.17 5.8.21, 4.16.17
  31. Unauthenticated Craft CMS users can trigger a database backup
    High CVE-2025-68456 >= 5.0.0-RC1, < 5.8.21, >= 3.0.0, < 4.16.17 5.8.21, 4.16.17
  32. Craft CMS Contains a Potential Remote Code Execution Vulnerability via Twig SSTI
    High CVE-2025-46731 >= 4.0.0-RC1, < 4.14.13, >= 5.0.0-RC1, < 5.6.15 4.14.13, 5.6.15
  33. Craft CMS Allows Remote Code Execution
    Critical · 10.0 Exploited in attacks CVE-2025-32432 >= 3.0.0-RC1, < 3.9.15, >= 4.0.0-RC1, < 4.14.15, >= 5.0.0-RC1, < 5.6.17 3.9.15, 4.14.15, 5.6.17
  34. Craft CMS has a potential RCE with a compromised security key
    High · 8.0 Exploited in attacks CVE-2025-23209 >= 5.0.0-RC1, < 5.5.8, >= 4.0.0-RC1, < 4.13.8 5.5.8, 4.13.8
  35. Craft CMS has potential RCE when PHP `register_argc_argv` config setting is enabled
    Critical · 9.8 Exploited in attacks CVE-2024-56145 >= 5.0.0-RC1, < 5.5.2, >= 4.0.0-RC1, < 4.13.2, >= 3.0.0, < 3.9.14 5.5.2, 4.13.2, 3.9.14
  36. Craft CMS vulnerable to Potential Remote Code Execution via missing path normalization & Twig SSTI
    High · 7.2 CVE-2024-52293 >= 4.0.0-RC1, < 4.12.2, >= 5.0.0-RC1, < 5.4.3 4.12.2, 5.4.3
  37. Craft CMS Arbitrary System File Read
    High · 7.7 CVE-2024-52292 >= 5.0.0-alpha.1, < 5.4.9, >= 3.5.13, < 4.12.8 5.4.9, 4.12.8
  38. Local File System Validation Bypass Leading to File Overwrite, Sensitive File Access, and Potential Code Execution
    High · 8.4 CVE-2024-52291 >= 5.0.0-RC1, < 5.4.6, >= 4.0.0-RC1, < 4.12.5 5.4.6, 4.12.5
  39. Craft CMS SQL injection vulnerability via the GraphQL API endpoint
    Critical · 9.8 CVE-2024-37843 <= 3.7.31 no fix
  40. Craft CMS Feed-Me
    High · 7.5 CVE-2023-36260 < 4.6.2 4.6.2
  41. Craft CMS Remote Code Execution vulnerability
    Critical · 10.0 CVE-2023-41892 >= 4.0.0-RC1, < 4.4.15 4.4.15
  42. Craft CMS vulnerable to Remote Code Execution via validatePath bypass
    High · 7.2 CVE-2023-40035 >= 4.0.0-RC1, < 4.4.15, >= 3.0.0, < 3.8.15 4.4.15, 3.8.15
  43. Craft CMS vulnerable to Remote Code Execution via unrestricted file extension
    High · 7.2 CVE-2023-32679 >= 4.0.0, < 4.4.6 4.4.6
  44. CraftCMS allows remote attacker to execute arbitrary code via crafted script to Section parameter
    High · 8.8 CVE-2023-30130 <= 3.8.1 no fix
  45. Craft CMS discloses password hashes
    High · 7.5 CVE-2022-37783 >= 3.0.0, < 3.7.33 3.7.33
  46. Craft CMS possibility of brute force attempts
    Critical · 9.8 CVE-2019-15929 < 3.1.7 3.1.7
  47. Craft CMS Vulnerable to Server-Side Template Injection
    High · 7.2 CVE-2018-20465 <= 3.0.34 no fix
  48. Craft CMS PHP Code Injection Vulnerability
    High · 8.8 CVE-2018-3814 <= 2.6.3000 no fix
  49. Improper account password reset in Craft CMS
    High · 8.8 CVE-2022-29933 < 3.7.36 3.7.36
  50. CSV Injection Vulnerability
    High · 8.8 CVE-2021-41824 >= 3.4.0, < 3.7.14 3.7.14
  51. Craft CMS Remote Code Injection
    Critical · 9.8 CVE-2021-27903 < 3.6.7 3.6.7

Know which vulnerabilities affect your application

With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.

Connect your application
DockRay newsletter

Application security in your inbox

Important vulnerabilities, actionable guidance and practical advice for your applications. Choose your technologies and follow what matters to your project.

  • A daily digest of new vulnerabilities, critical ones included.
  • Notifications about important updates.
  • Practical advice on application security and monitoring.

Leave empty to receive updates for every technology.

Privacy policy

Free to subscribe. Unsubscribe with one click in any email.