CVE-2026-58200: @jhb.software/payload-cloudinary-plugin: Arbitrary Cloudinary API Parameter Signing
Payload Plugins is a collection of plugins designed to enhance Payload CMS. From 0.3.0 until 0.4.0, @jhb.software/payload-cloudinary-plugin deployments with clientUploads enabled expose POST /api/cloudinary-generate-signature, whose handler in cloudinary/src/getGenerateSignature.ts passes attacker-controlled body.paramsToSign directly to cloudinary.utils.apisignrequest without a key allowlist, collection policy, timestamp freshness check, or configured-folder enforcement. Any authenticated Payload user can obtain a valid Cloudinary HMAC-SHA1 signature for unauthorized parameters such as overwrite, type, notificationurl, invalidate, folder, and publicid. The signature can authorize asset replacement, upload visibility changes, callbacks to attacker-selected URLs, cache invalidation, and uploads outside the intended folder. The client-visible Cloudinary API key is expected by the upload design, but the unrestricted server-side signature supplies the authorization value needed to complete these operations. This vulnerability is fixed in 0.4.0.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
@jhb.software/payload-cloudinary-pluginto a version that resolves this vulnerability.Fixed in 0.4.0
Event History
Frequently Asked Questions
Who can exploit this issue?
Any authenticated Payload user can request signatures for attacker-controlled Cloudinary API parameters when clientUploads is enabled. The issue is exposed through the POST /api/cloudinary-generate-signature endpoint.
Are deployments using the default upload flow affected?
Deployments are affected when they use @jhb.software/payload-cloudinary-plugin versions from 0.3.0 up to, but not including, 0.4.0 and have clientUploads enabled. The client-visible Cloudinary API key alone is expected by the design; the risk comes from the server issuing unrestricted signatures.
What can an attacker do with a generated signature?
A valid signature can authorize unauthorized Cloudinary operations including replacing assets, changing upload visibility, sending callbacks to attacker-selected URLs, invalidating caches, and uploading outside the intended folder. Parameters identified as signable include overwrite, type, notification_url, invalidate, folder, and public_id.
What is the remediation?
Upgrade to version 0.4.0, which fixes the issue. If upgrading is not immediately possible, the provided data does not specify a supported workaround.