Payload external upload trust validation issue

Impact

Under certain external upload configurations, Payload could send authentication data to a destination that was not verified as trusted. If the affected request contained a valid session, this could expose that session to an unintended recipient.

You are affected if:

• You have enabled external URL-based upload retrieval, where authenticated requests can trigger it.

Patches

Payload now validates the destination before forwarding authentication data and reapplies that validation when a request changes destination.

Users should upgrade Payload packages to >= 3.90.0 or >= 4.0.0-canary.34.

Workarounds

It is recommended to update all Payload packages to >= 3.90.0 or >= 4.0.0-canary.34.

If you cannot, a valid workaround exists:

• Disable external URL-based upload retrieval where practical.
• If you cannot disable it, configure the upload header filter to remove authentication data from outbound file requests.
• Restrict access to the affected upload functionality.