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Medium

Craft CMS: Authenticated "assets/preview-thumb" discloses signed fallback transform preview link to CP users without asset-view permission

  • Disclosed: 06.07.2026
  • Updated: 11.10.2026 10:22

Summary

A user with Control Panel access but without permission to view a target private asset can call assets/preview-thumb and receive preview HTML that contains a signed fallback transform link for that private asset.

Details

Root-cause analysis:

  1. The endpoint accepts an attacker-controlled assetId.
  2. Asset is resolved, and thumbnail HTML is returned.
  3. No explicit asset-view permission check is performed before preview generation.

Impact

Type:

  1. Missing authorization
  2. Unauthorized preview-link disclosure

Affected deployments:

  1. Craft sites with control panel users who have partial permissions and private assets.

Security consequence:

  1. A control panel user without asset-view permission can still obtain signed preview transform link data for private assets.
  2. This may increase private asset exposure risk depending on deployment and endpoint chaining.

Resources

https://github.com/craftcms/cms/commit/d30df3112220db1ffd6726a3ed11857014c7fb27

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package craftcms/cms >= 4.0.0-RC1, < 4.17.8, >= 5.0.0-RC1, < 5.9.14 4.17.8, 5.9.14

References

CVSS score -
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness (CWE)
CWE-200, CWE-862
Platform
Composer
Package
craftcms/cms
Disclosed
06.07.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-x76w-8c62-48mg - 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: 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
  8. Craft CMS: Authenticated "assets/preview-thumb" discloses signed fallback transform preview link to CP users without asset-view permission this entry
    Medium CVE-2026-56384 >= 4.0.0-RC1, < 4.17.8, >= 5.0.0-RC1, < 5.9.14 4.17.8, 5.9.14
  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
Show more (11) Showing 40 of 51

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