Craft CMS may expose private assets through anonymous "generate transform" calls via transform URL

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

2.7 · 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 · score source

EPSS

• CVE-2026-33160: 0.36% estimated exploitation activity in the next 30 days; percentile 29.95 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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 https://github.com/craftcms/cms/commit/7290d91639e

Published by the source

24 Mar 2026, 16:59 UTC

Last modified by the source

25 Mar 2026, 21:00 UTC

Source last checked

26 Oct 2026, 14:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-5pgf-h923-m958

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# Patch Next advisory brief: CVE-2026-33160

Advisory: Craft CMS may expose private assets through anonymous "generate transform" calls via transform URL
IDs: CVE-2026-33160, GHSA-5pgf-h923-m958
Record: https://patchnext.com/advisories/cve-2026-33160 (revision 1, source checked 26 Oct 2026, 14:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: craftcms/cms 5.9.14, 4.17.8. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist craftcms/cms: affected >= 5.0.0-RC1, <= 5.9.13; >= 4.0.0-RC1, <= 4.17.7; fixed in 5.9.14, 4.17.8

## Suggested inspection (read-only)
- Packagist craftcms/cms: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on craftcms/cms.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-5pgf-h923-m958 (GitHub-reviewed advisory GHSA-5pgf-h923-m958 lists affected ranges: Packagist craftcms/cms >=5.0.0-RC1 =4.0.0-RC1 <=4.17.7)

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