Craft CMS may expose private assets through anonymous "generate transform" calls via transform URL
Summary
An unauthenticated user can call assets/generate-transform with a private assetId, receive a valid transform URL, and fetch transformed image bytes.
The endpoint is anonymous and does not enforce per-asset authorization before returning the transform URL.
Details
Root cause:
- Anonymous endpoint accepts user-controlled asset reference.
- It creates and returns a transform URL for that asset without checking access rights.
- If the transform output is reachable, guest users can read content derived from private assets.
Who is impacted:
- Installations where private source assets can be transformed and transform URLs are reachable.
Security consequence:
- Anonymous users can obtain content derived from private assets without authentication.
Resources
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | craftcms/cms | >= 5.0.0-RC1, < 5.9.14, >= 4.0.0-RC1, < 4.17.8 | 5.9.14, 4.17.8 |
References
- https://github.com/craftcms/cms/security/advisories/GHSA-5pgf-h923-m958
- https://nvd.nist.gov/vuln/detail/CVE-2026-33160
- https://github.com/craftcms/cms/commit/7290d91639e5e3a4f7e221dfbef95c9b77331860
- https://github.com/craftcms/cms
- https://github.com/craftcms/cms/releases/tag/4.17.8
- https://github.com/craftcms/cms/releases/tag/5.9.14
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U- Weakness (CWE)
CWE-639, CWE-862- Platform
- Composer
- Package
craftcms/cms- Disclosed
- 24.03.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-5pgf-h923-m958 - 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.
- 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
- 2021: 3
- 2022: 22
- 2023: 13
- 2024: 9
- 2025: 6
- 2026: 74
-
Craft CMS may expose private assets through anonymous "generate transform" calls via transform URL this entry
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.