GIVE YOUR AGENT THE EVIDENCE

Set up in your agent.

One prompt to get started. Paste it into your coding agent to connect cve.new through MCP and bring vulnerability context into your workflow.

Your agent needs remote MCP support and access to https://cve.new/mcp.

Read the setup guide

GIVE YOUR AGENT THE EVIDENCE

Investigate in your agent.

Turn this advisory into a focused investigation. Ask your agent to check your project’s versions, explain the evidence, and suggest a compatible fix.

Your agent needs remote MCP support and access to https://cve.new/mcp.

Read the setup guide

cve.new
Check your stack
GHSA-x76w-8c62-48mgmedium5.3

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

Impact

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.

Source excerpt · OSV

Affected packages

Start with the recorded fix for your release branch. Check your installed version and test compatibility before upgrading. Fixing this advisory does not rule out other vulnerabilities in the release.

craftcms/cms Packagist
Affected rangeRecorded fix
From 4.0.0-RC1 before 4.17.8Ecosystem versions4.17.8
From 5.0.0-RC1 before 5.9.14Ecosystem versions5.9.14

Version evidence: OSV · GHSA-x76w-8c62-48mg

View original version evidence (400 explicit versions)

Original source description

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

References